Geology 
Library 

QD 
87 
B97p 


THE  LIBRARY 

OF 

THE  UNIVERSITY 
OF  CALIFORNIA 

LOS  ANGELES 


Tke  RALPH  D.  REED  LIBRARY 


DEPARTMENT  OF  GEOLOGY 

UNIVERSITY  of  CALIFORNIA 
LOS  ANGELES,  CALIF. 


of  Oil  Companies  of  Southern  Cali- 
fornia, Alumni  and  Faculty  of  Geology  Depart- 
ment and  University  Library. 

1940 


§/•/'« 

M  «  r  r  o  e  is/, 
I  i-  i.  /  *J  o  i  <>. 


WORKS    OF 
PROF.  G.   MONTAGUE    BUTLER 

PUBLISHED   BY 

JOHN  WILEY  &  SONS 


A  Pocket  Handbook  of  Minerals. 

Designed  for  Use  in  the  Field  or  Classroom,  with 
little  reference  to  Chemical  Tests.  Second  Edition. 
x6mo,  ix-t-3ii  pages,  illustrated.  Leather,  $;.oo. 

Pocket  Handbook  of  Blowpipe  Analysis. 

Designed  for  the  Use  of  Students  and  Prospectors 
with  the  idea  of  making  Oral  Instruction  unnec- 
essary. i6mo,  v+8o  pages.  Cloth,  js  cents  net. 


POCKET  HANDBOOK 

OF 

BLOWPIPE  ANALYSIS 

DESIGNED    FOR    THE    USE    OF 

STUDENTS  AND  PROSPECTORS  WITH   THE  IDEA  OF 
MAKING   ORAL   INSTRUCTION    UNNECESSARY 


BY 

G.   MONTAGUE   BUTLER,  E.M. 

Assistant  Professor  of  Geology  and  Mineralogy.  Colorado  School  of  Mines 
Golden,  Colorado;  Geologist,  Colorado  Geological  Survey 


FIRST    EDITION 
FIRST    THOUSAND 


NEW  YORK 

JOHN   WILEY  &    SONS 

LONDON-:    CHAPMAN  &   HALL,   LIMITED 
1910 


Copyright,  1 9'°. 

BY 

G.  MONTAGUE   BUTLER 


THE   SCIENTIFIC   PRESS 


PREFACE 


THIS  little  book  was  written,  primarily,  to  satisfy 
the  demands  of  those  instructors  who  have  been 
using  the  author's  Pocket  Handbook  of  Minerals  as 
a  text-book  for  courses  in  mineralogy.  While  there 
is  no  doubt  that  a  thorough  knowledge  of  the  physical 
characteristics  of  minerals  should  be  the  end  sought 
by  all  teachers  and  students  of  this  subject,  it  is 
often  desirable  to  be  able  to  fall  back  upon  other 
simple  tests  in  corroboration  of  conclusions  reached 
by  observation,  or  when  studying  an  unfamiliar 
mineral.  For  this  purpose,  blowpipe  analysis  is 
very  satisfactory,  since  the  necessary  implements 
and  reagents  are  comparatively  few  and  simple  and 
may  be  so  selected  as  to  be  portable. 

While   there  are  many  works  on   this  subject, 

1  they  are  either  too  comprehensive  for  the  purpose 
for  which  this  is  intended,  or  else  form  merely  an 

!   introductory  chapter  to  a  work  on  mineralogy.     In 

I   both  cases,  their  purchase  entails  a  needlessly  high 
expense,  and   their   directions   and  statements  are 

!  often  so  vague  and  incomplete  as  to  require  continual 

-  explanation  by  an  instructor. 

iii 

733801 


iv  PREFACE 

No  originality  is  claimed  for  the  tests  themselves 
as  given  in  this  pamphlet;  they  are  the  same  as  are 
included  in  all  books  on  the  subject,  and  as  have 
been  taught  in  the  Colorado  School  of  Mines  for 
years  by  Professor  H.  B.  Patton.  Such  modifications 
and  additions  have  been  made,  however,  as  experi- 
ence has  proven  desirable.  The  text  and  plan  of 
the  work  are,  of  course,  original,  and  so  are  most  of 
the  data  included  in  the  notes  on  the  various  tests. 
Utility  and  conciseness  have  been  the  ends  sought, 
and  it  is  believed  that  no  superfluous  details  have 
been  included  and  that  nothing  essential  has  been 
omitted. 

Secondarily,  the  book  was  written  to  satisfy 
the  needs  of  miners  and  prospectors,  whose  first 
question  on  finding  a  new  mineral  is,  "What  does 
it  contain  ?"  It  is  so  elementary  in  its  nature  and 
the  directions  are  so  complete  that  anyone  with 
a  common-school  education,  the  proper  instruments, 
and  this  book  should  be  able  in  most  cases  to  answer 
this  question  for  himself.  It  was  for  this  class  of 
readers  alone  that  Chapters  V  and  VI  were  included. 

Finally,  it  is  believed  that  assayers  and  chemists 
will  find  the  book  useful  in  making  preliminary 
examinations  of  unknown  substances. 


TABLE  OF  CONTENTS 


CHAPTER  I 

PAGE 

BLOWPIPE  INSTRUMENTS,  REAGENTS  AND  OPERATIONS i 

CHAPTER  II 

METHODS  OF   TESTING  FOR  THE  VARIOUS  ELEMENTS  WITH 

THE  BLOWPIPE 9 

CHAPTER  III 
OUTLINE  FOR  QUALITATIVE  BLOWPIPE  ANALYSIS 42 

CHAPTER  IV 

INDEX   TO  ALL  OF  THE   TESTS   YIELDED  BY  THE  VARIOUS 

ELEMENTS 47 


THE   DETERMINATION  OF   MINERALS  BY  MEANS   OF   THE 

BLOWPIPE 50 

CHAPTKR  VI 
THE  ELEMENTARY  PRINCIPLES  OF  CHEMISTRY 62 

TABLE  OF  ELEMENTS  WITH  THEIR  SYMBOLS   AND    ATOMIC 
WEIGHTS 73 

INDEX .     74 


BLOWPIPE    ANALYSIS 


CHAPTER  I 

BLOWPIPE  INSTRUMENTS,  REAGENTS  AND 
OPERATIONS 

NEARLY  all  dealers  in  assayers'  or  chemists'  sup- 
plies cany  sets  and  separate  pieces  of  blowpipe 
apparatus,  and  many  pieces  may  be  obtained 
elsewhere,  as  will  be  seen  from  the  following  brief 
description  of  the  articles  used  in  the  operations 
later  described.  Most  of  the  sets  now  on  the  market 
are  either  too  elaborate,  too  bulky,  or  else  are 
impractical,  and  great  care  should  be  exercised 
in  their  selection. 

Blowpipe.  Many  types  are  manufactured,  and 
each  may  have  its  own  peculiar  advantages,  but 
almost  any  one  in  which  the  aperture  is  not 
too  large  or  too  small  will  answer  the  purpose. 
The  most  satisfactory  type  has  a  trumpet-shaped 
mouthpiece,  a  small  chamber  in  which  the  saliva 
may  accumulate,  and  a  removable  tip.  In  portable 
sets  it  is  not  practicable  to  provide  a  blowpipe 
with  a  trumpet-shaped  mouthpiece,  however,  and 


2  BLOWPIPE  A. \  A  LYSIS 

this  may  be  dispensed  with,  although  somewhat 
easier  on  the  lip  muscles.  Some  makes  are  pro- 
vided with  platinum  tips,  but  this  is  an  unnecessary 
refinement  unless  a  great  deal  of  work  is  to  be  done. 

A  piece  of  very  fine  platinum  or  steel  wire  is 
the  best  implement  with  which  to  clean  out  a 
clogged  tip. 

Lamps.  It  is  desirable,  although  not  absolutely 
essential,  to  have  two  lamps,  one  for  oil  and  the 
other  for  alcohol.  The  latter  is  handier  than  the 
oil  lamp  for  a  few  operations  which  will  be  men- 
tioned later,  but  in  every  case  it  can  be  replaced 
by  the  oil  lamp  without  material  disadvantage. 

The  oil  lamp  should  have  a  rectangular  wick 
opening  about  half  an  inch  long  and  less  than  half 
as  wide;  the  wick  opening  in  the  alcohol  lamp 
may  be  of  any  shape.  Care  should  be  taken  (par- 
ticularly"  with  the  oil  lamp)  not  to  have  the  wick 
so  tight  as  to  impede  the  flow  of  oil,  to  trim  off 
charred  wick  or  irregularities  as  fast  as  they  form, 
and  to  keep  the  wick  just  high  enough  not  to  smoke. 
The  best  fuel  for  the  oil  lamp  is  a  mixture  com- 
posed of  two  parts  of  lard  oil  and  one  part  of  kero- 
sene. This  solidifies  in  very  cold  weather,  but 
thaws  out  soon  after  lighting  the  lamp. 

Any  other  flame,  such  as  that  from  a  candle 
or  kerosene  lamp,  may  be  used  instead  of  these 
lamps,  and  it  is  often  necessary  to  resort  to  these 
in  the  field,  but  the  lamps  and  oil  described  will 


INSTRUMENTS,  REAGENTS,  OPERATIONS       3 

give  the  best  results  in  the  laboratory.  In  some 
places  gas  blowpipes  are  used,  but  one  who  has 
attained  proficiency  with  such  apparatus  is  lost  in 
the  field,  so  simpler  instruments  are  preferable. 

Platinum-tipped'  Forceps.  The  most  convenient 
type  of  these  has  tips  of  platinum  on  one  end  and  of 
base  metal  on  the  other,  the  platinum-tipped  end 
being  provided  with  a  spring  which  holds  the  tips 
together.  Precautions  as  to  the  use  of  these  forceps 
are  given  later.  They  soon  become  discolored 
with  use,  but,  if  the  precautions  just  mentioned 
are  observed,  this  will  not  harm  them.  They  may 
be  cleaned  by  using  very  fine  sandpaper  or  scraping 
with  a  knife-blade. 

Platinum  Wire  and  Holder.  The  wire  should 
be  of  about  26  American  or  B.  &  S.  Wire  Gauge 
in  thickness,  and  should  be  cut  into  pieces  between 
two  and  three  inches  long.  The  holder  may  be  a 
glass  tube  into  which  one  end  of  the  wire  is  fused, 
but  a  mechanical  holder  with  a  hollow  handle  in 
which  extra  wires  may  be  kept  is  more  convenient. 
Precautions  concerning  the  use  of  the  platinum 
wire  are  given  later. 

Charcoal  Supports.  These  should  be  made  from 
soft  wood  and  should  be  at  least  three  inches 
long,  preferably  more.  They  should  not  fissure, 
break,  smoke,  or  ignite  readily  in  the  flame,  and 
should  leave  little  ash  when  burned. 

Unless   liquid  reagents  have   been   used   on  the 


4  BLOWPIPE  ANALYSIS 

charcoal  in  tests  resulting  successfully,  the  charcoal 
may  be  used  many  times  by  scraping  oil  the  surface 
and  the  deposits  formed  thereon.  Where  liquids 
have  been  used  in  successful  tests,  they  are  apt  to 
sink  for  a  considerable  distance  into  the  charcoal, 
and  to  cause  a  duplication  of  the  test  even  after 
a  considerable  depth  of  the  charcoal  has  been 
removed. 

Closed  Tubes.  These  are  usually  formed  of 
three-eighths  inch  glass  tubing  three  or  four  inches 
long,  an  inch  of  one  end  being  bent  to  one  side 
and  closed  by  fusion.  Equally  satisfactory  results 
are  secured  from  an  implement  formed  by  fusing 
together  one  end  of  an  open  tube  (see  below). 
Closed  tubes  cannot  well  be  cleaned  and  should 
be  discarded  after  use.  A  strip  of  asbestos,  or  even 
paper,  wrapped  around  the  upper  part  of  the  tube 
makes  a  convenient  holder  for  hot  tubes. 

Open  Tubes.  These  are  pieces  of  three-eighths 
inch  glass  tubing  three  to  five  inches  long.  They 
should  be  discarded  after  use  unless  the  results  have 
been  negative,  when  the  other  end  may  be  used  for  a 
new  test.  The  asbestos  or  paper  holder  mentioned 
above  should  be  used  for  hot  tubes. 

Miscellaneous.  A  small  slab  of  hard  steel  with 
at  least  one  polished  surface  for  use  as  an  anvil. 

A  small  steel  hammer  with  a  flat  face. 

A  small  horseshoe  or  bar  magnet.  The  latter 
may  be  procured  with  one  end  so  shaped  as  to 


INSTRUMENTS,  REAGENTS,  OPERATIONS        5 

form  a  charcoal  borer,  but  this  is  not  neces- 
sary. 

Test-tubes. 

A  hand-lens. 

A  small  piece  of  dark  blue  glass. 

Reagent  Bottles  and  Reagents.  Wide-mouth,  glass- 
stoppered  bottles  are  the  best  in  which  to  keep  the 
dry  reagents,  which  should  include  powdered  (pref- 
erably dehydrated)  borax,  sodium  carbonate,  sodium 
ammonium  phosphate  (salt  of  phosphorus),  acid 
potassium  sulphate,  and  bismuth  flux  (equal  pro- 
portions of  potassium  iodide  and  sulphur). 

The  wet  reagents  should  be  kept  in  glass  bottles 
with  glass  stoppers,  and  a  dropper  stopper  will 
be  found  a  great  convenience,  although  a  satis- 
factory dropper  can  be  easily  made  from  a  small 
glass  tube.  The  following  reagents  are  needed: 

Hydrochloric  (muriatic)  acid.  The  concentrated 
acid  should  be  diluted  with  an  equal  volume  of 
water  for  most  purposes. 

Xitric  acid.  The  concentrated  acid  is  usually 
employed. 

Sulphuric  acid  (oil  of  vitriol).  For  most  purposes 
the.  concentrated  acid  should  be  diluted  with  four 
volumes  of  water.  A  great  deal  of  heat  is  generated 
when  water  and  sulphuric  acid  are  mixed,  and  this 
should  be  done  with  care.  The  acid  should  be 
added  gradually  to  the  water,  stirring  constantly. 
Water  should  never  be  added  to  sulphuric  acid. 


6  BLOWPIPE  ANALYSIS 

Cobalt  nitrate.  The  dry  salt  should  be  dissolved 
in  ten  parts  of  water  for  use. 

All  acids  should  be  handled  with  care,  as  they 
are  more  or  less  corrosive  and  are  capable  of  inflict- 
ing painful  injuries  when  spilled  on  the  skin. 
When  this  happens,  or  if  they  fall  upon  fabrics, 
their  effects  may  be  neutralized  by  moistening  with 
ammonia  and  then  washing  thoroughly  with  water. 

Blowpipe  Operations.  The  blowpipe  is  used  for 
the  purpose  of  concentrating  the  flame  into  a  long, 
slender  cone  which  can  be  readily  directed  against 
the  substance  to  be  heated.  It  is  very  important 
that  the  blast  be  continuous  and  uniform,  although 
this  may  seem  very  difficult  at  first.  The  blast  is 
not  produced  by  the  lungs,  but  results  from  a  bel- 
lows-like action  of  the  distended  cheeks.  During 
the  operation,  air  is  inhaled  only  through  the  nose, 
and  is  exhaled  largely  through  the  mouth  and  the 
blowpipe.  Before  trying  to  use  that  instrument, 
distend  the  cheeks,  and,  keeping  the  mouth  closed, 
breathe  through  the  nose  for  a  moment;  then  open 
the  lips  just  enough  to  allow  a  little  air  to  escape 
slowly,  and  admit  air  from  the  lungs  by  a  kind  of 
gulping  action  just  fast  enough  to  keep  the  cheeks 
fully  distended.  This  may  take  some  practice, 
but,  when  it  is  possible  to  allow  air  to  escape  con- 
tinuously from  the  mouth  in  this  way  no  matter 
whether  it  is  being  exhaled  or  inhaled  through  the 
nostrils,  it  is  time  to  begin  to  use  the  blowpipe. 


INSTRUMENTS,   REAGENTS,  OPERATIONS       7 

Producing  the  Oxidizing  Flame.  Place  the  oil 
lamp  so  that  the  longer  dimension  of  the  wick  is 
from  right  to  left,  and  set  its  right-hand  edge  upon 
a  pencil  or  some  other  low  support  so  that  it  will 
tip  somewhat  to  the  left.  Insert  the  tip  of  the  blow- 
pipe about  one-eighth  of  an  inch  within  and  just 
above  the  right-hand  side  of  the  wick,  and  blow 
steadily  parallel  to  the  wick,  directing  the  flame 
to  the  left,  and  producing  a  clear  blue  flame  about 
an  inch  long.  If  all  of  the  flame  cannot  be  thus 
diverted  to  the  left,  or  if  there  are  yellow  streaks 
in  the  flame,  trim  or  lower  the  wick.  If  the  whole 
flame  is  inclined  to  be  yellow,  move  the  tip  of  the 
blowpipe  a  trifle  to  the  left.  If  it  is  impossible  to 
produce  a  flame  approaching  the  length  mentioned 
above,  the  opening  in  the  end  of  the  blowpipe  is 
too  small,  and  this  opening  is  too  large  when  a 
very  long,  hissing  flame  is  produced.  In  order  to 
succeed  in  blowing  a  steady  flame,  the  hand  must 
rest  upon  some  support,  or  the  third  and  fourth 
fingers  may  be  placed  against  the  lamp. 

IP  analytical  operations  it  is  sometimes  desirable 
to  oxidize  substances  to  be  tested,  and  at  other 
times  the  aim  is  to  reduce  them  to  the  metallic 
condition;  either  result  can  be  more  or  less  readily 
obtained  with  the  blowpipe.  ( 

A  flame  produced  in  the  manner  above  described 
is  called  an  oxidizing  flame,  but  the  action  of  all 
portions  of  such  a  flame  is  not  oxidizing.  The  blue 


8  BLOWPIPE  ANALYSIS 

cone  contains  considerable  carbon  monoxide  and 
is  feebly  reducing  in  its  action,  but  just  outside  of  the 
blue  cone  at  the  tip  of  the  flame  is  an  extremely 
hot  but  nearly  colorless  zone  which  is  strongly 
oxidizing  because  of  the  free  oxygen  there  present, 
and  anything  held  in  this  zone  about  a  quarter  of 
an  inch  from  the  tip  of  the  blue  flame  will  be  in  the 
most  favorable  position  for  oxidation. 

The  oxidizing  flame  is  hotter  than  the  reducing, 
and  the  hottest  part  of  this  flame  is  just  outside  of 
the  blue  cone.  In  the  absence  of  other  instructions, 
substances  should  always  be  heated  there. 

Producing  the  Reducing  Flame.  Hold  the  tip  of 
the  blowpipe  about  one-sixteenth  of  an  inch  above 
and  to  the  right  of  the  wick,  and  a  long,  yellow 
flame  containing  much  unconsumed  carbon  will 
be  produced.  This  is  sometimes  called  the  smoky 
reducing  flame.  Where  greater  heat  is  required, 
the  inner  cone  of  the  oxidizing  flame  should  be  used. 
The  strongest  reducing  action  will  take  place  at  the 
tip  of,  and  within,  the  yellow  cone  of  the  reducing 
flame. 

Other  Operations.  These  will  be  described  in 
detail  when  the  various  tests  are  discussed. 


CHAPTER  II 

METHODS  OF  TESTING  FOR  THE  VARIOUS 
ELEMENTS  WITH  THE  BLOWPIPE 

THE  methods  of  testing  for  the  various  elements 
with    the    blowpipe    comprise    blowpipe    analysis, 
and  many  tests  are  included  under  this  term,  includ- 
ing a  few  in  which  the  blowpipe  is  not  required. 
The  most  useful  are  included  in  the  following  list, 
and  will  be  discussed  in  the  order  named: 
I.  Treatment  on  charcoal  without  flux. 
II.  Treatment  on  charcoal  with  flux. 

III.  Tests  in  closed  tubes. 

IV.  Tests  in  open  tubes. 

V.  Tests  with  borax  beads. 
VI.  Tests  with  salt  of  phosphorus  beads. 
VII.  Flame  tests. 
VIII.  Cobalt  nitrate  coloration  tests. 

IX.  Tests  with  acids. 

The  tests  given  should  make  it  possible  to  recog- 
nize the  following  elements  and  substances  in  most 
of  their  combinations: 

Aluminum  (Al),  antimony  (Sb),  arsenic  (As), 
barium  (Ba),  bismuth  (Bi),  boron  (B),  cadmium 
(Cd),  calcium  (Ca),  chromium  (Cr),  cobalt  (Co), 

9 


10  BLOWPIPE  ANALYSIS 

copper  (Cu),  flourine  (F),  gold  (Au),  iron  (Fe),  lead 
(Pb),  lithium  (Li),  magnesium  (Mg),  manganese 
(Mn),  mercury  (Hg),  molybdenum  (Mo),  nickel 
(Ni),  phosphorus  (P),  potassium  (K),  selenium  (Se), 
silver  (Ag),  sodium  (Na),  strontium  (Sr),  sulphur 
(S),  tellurium  (Te),  tin  (Sn),  titanium  (Ti),  tung- 
sten (W),  uranium  (U),  vanadium  (V),  zinc  (Zn), 
and  water,  silicates,  and  carbonates. 

i.  TREATMENT  ON  CHARCOAL  WITHOUT  FLUX 

A  piece,  the  size  of  a  BB  shot  or  smaller,  of  the 
substance  to  be  tested  is  pressed  into  the  face  of  the 
charcoal  about  half  an  inch  from  one  end,  or  it 
may  be  placed  in  a  tiny  cavity  formed  at  that  point, 
the  object  of  embedding  it  somewhat  in  the  charcoal 
being  merely  to  prevent  the  particle  from  sliding 
off  or  being  blown  away.  The  charcoal  is  then 
held  in  the  left  hand,  pointing  right  and  left,  and 
the  blowpipe  flame  is  blown  upon  the  particle, 
which  should  be  at  the  right  end,  in  such  a  manner 
that  the  flame  is  not  parallel  with  the  charcoal  but 
impinges  downward  upon  the  particle  at  a  small 


The  piece  tested  is  known  as  the  assay. 

Heat  the  assay  strongly  for  a  minute  or  more  in 
the  oxidizing  flame,  noting  any  odor  or  colored 
flame  that  may  be  given  off,  and  then  examine  the 
charcoal  for  any  coatings,  known  as  sublimates,  that 


METHODS  OF  TESTING  11 

may  have  been  deposited  thereon.  If  no  very 
positive  results  are  thus  obtained,  repeat  the  opera- 
tion, using  the  reducing  flame. 

Care  must  be  taken  not  to  place  the  assay  in  deep 
holes  that  have  been  burned  or  scraped  into  the 
charcoal.  If  this  is  done,  the  volatilized  material 
will  shoot  up  into  the  air,  and  no  sublimate  will 
deposit  on  the  charcoal. 

Most  charcoal  forms  a  little  white  ash  when 
burned;  this  should  not  be  confused  with  a  sub- 
limate. 

Decrepitation  (flying  to  pieces)  of  the  assay  may 
sometimes  be  prevented  by  heating  it  very  slowly, 
i.e.,  holding  it  three  or  four  inches  from  the  flame 
at  first  and  gradually  bringing  it  nearer.  Another 
method,  often  satisfactory,  consists  of  blowing 
the  flame  against  the  upper  part  of  the  end  of  the 
stick  of  charcoal  until  it  is  red  hot,  thus  gradually 
warming  the  assay. 

If  the  substance  still  decrepitates  or  if  no  results 
are  obtained  by  the  above  methods  of  treatment, 
powder  the  material  to  be  tested  very  fine  and  press 
a  small  amount  of  the  powder  onto  one  end  of  the 
charcoal,  using  a  knife  blade  or  spatula  for  this 
purpose  and  forming  a  flat  cake  of  the  powder. 
Then  proceed  as  before.  If  the  material  still 
decrepitates,  moisten  it  with  water  and  heat  very 
slowly. 

Since  chlorides  of  lead,  copper,  and  other  sub- 


12  BLOWPIPE  AX. -I LYSIS 

stances  yield  white  sublimates  on  charcoal  that  may 
be  confused  with  those  mentioned  below,  it  is 
essential  that  the  charcoal  tests  be  made  before 
any  hydrochloric  acid  has  been  put  on  the  substance 
to  be  tested. 

Not  only  is  it  necessary  to  note  the  color  of 
any  sublimates  produced,  but  their  volatility 
should  also  be  tested,  as  some  are  very  volatile 
(can  be  burned  off  by  applying  the  blowpipe 
flame  for  a  fraction  of  a  second)  while  others 
are  quite  non-volatile  (require  the  application 
of  considerable  heat  to  entirely  remove  them)  in 
the  oxidizing  flame,  which  should  be  used  for  this 
test. 

The  results  obtained  by  any  of  the  above  means 
may  be  thus  interpreted: 

a.  White,  very  volatile,  light  sublimate,  depos- 

ited some  distance  from  the  assay.  Strong 
odor  of  garlic As 

b.  White  sublimate  with  a  blue  border  deposited 

close  to  the  assay,  heavier  and  less  volatile 
than  that  yielded  by  As.  Assay  will  often 
continue  to  give  forth  white  fumes  after 
heating  has  ceased Sb 

c.  White,  fairly  easily  volatilized,  heavy  sub- 

limate near  the  assay,  shading  into  a 
lighter,  more  volatile  coating  further  out. 
Odor  of  garlic Sb  with  As 


METHODS  OF  TESTING  13 

d.  White  and  yellowish,  crystalline   (particles 

are  coarse  and  sharp-edged)  sublimate 
which  is  changed  to  a  deep  ultramarine  blue 
if  touched  for  a,  fraction  of  a  second  with  the 
reducing  flame.  A  copper-red  coating  may 
form  close  to  the  assay Mo 

(Prolonged  heating  with  the  oxidizing  flame 
is  required  to  obtain  the  white  sublimate,  which  is 
yielded  satisfactorily  only  by  the  sulphide — molyb- 
denite.) 

e.  White  when  cold,  yellow  when  hot,  light, 

non-volatile  sublimate,  which,  if  moistened 
with  cobalt  nitrate  and  heated,  will  become 
bright  green  when  cold Zn 

(This  test  should  be  conducted  as  follows:  Pul- 
verize the  material  very  fine  and  heat  strongly  and 
for  some  time  with  the  reducing  flame;  moisten 
the  charcoal  where  the  sublimate  has  formed,  or 
should  form,  with  a  little  cobalt  nitrate;  reheat  the 
assay  strongly  with  the  reducing  flame,  and,  if  Zn  be 
present  in  any  form  but  the  silicate,  enough  heat 
will  reach  the  spot  moistened  to  turn  it  bright  green 
when  cold.) 

/.  White,  heavy  sublimate  with  a  blue  outer 
border  close  to  the  assay,  a  yellowish  gray 
coating  far  from  the  assay,  and  a  black 
band  between  the  two.  All  are  easily  vola- 
tile, burning  off  with  a  light  bluish  green 
flame,  which  is  also  yielded  by  the  assay  Te 

g.  White  when  cold,  yellowish  when  hot,  light, 


14  BLOWPIPE  ANALYSIS 

non-volatile  sublimate,  which,  if  moistened 
with  cobalt  nitrate  and  heated,  will  become 
a  dull  bluish  green  when  cold Sn 

(This  test  should  be  conducted  exactly  like  the 
one  for  Zn,  described  above.)  I* 

h.  Yellow,  volatile  sublimate,  inclining  toward 
orange  when  hot,  with  a  very  volatile  outer 
fringe  of  white.  Yellow  fumes  and  odor 
of  garlic As  with  S 

(This  result  is  obtained  when  a  sulphide  of  As  is 
heated  and  volatilized  too  rapidly  to  permit  of  com- 
plete oxidation.  Some  of  the  material  is  volatilized 
and  deposited  as  the  yellow  sulphide  of  As.) 

i.  Yellow  or  orange,  non-volatile  sublimate, 
often  with  a  bluish  white  outer  border, 
deposited  very  close  to  the  assay Pb 

j.  Yellow  or  orange,  non-volatile  sublimate, 
often  with  a  bluish  white  outer  fringe, 
deposited  very  close  to  the  assay Bi 

(Bi  is  much  rarer  than  Pb,  and  the  test  described 
alx)ve  may  in  the  majority  of  cases  be  interpreted 
as  indicating  Pb.  To  distinguish  with  certainty 
between  these  two  elements,  mix  the  powdered  sub- 
stance with  three  or  four  times  its  volume  of  "bis- 
muth flux"  (equal  proportions  of  potassium  iodide 
and  sulphur),  and  heat  on  charcoal  as  usual.  The 
sublimate  produced  by  Bi  will  be  yellow  near  the 
assay,  but  bordered  on  the  outer  edge  by  a  brilliant 
red,  which  will  be  missing  in  the  case  of  Pb.) 

k.  Brown,  volatile  sublimate  close  to  the  assay, 


METHODS  OF   TESTIXG  15 

bordered  by  a  very  volatile,  heavy  white 
sublimate.     Odor  of  garlic As 

(This  result  is  obtained  when  the  material  is 
heated  and  volatilized  too  rapidly  to  admit  of  com- 
plete oxidation  ojpthe  As.  The  brown  sublimate 
is  metallic  As.) 

I.  Brown,  fairly  volatile  sublimate  close  to  the 

assay Cd 

m.  Reddish  brown  outer  border  on  a  black  or 
steel-gray  volatile  sublimate.  A  curious 
and  indescribable,  but  characteristic,  odor 
and  a  blue  flame Se 

n.  Lilac  or  lilac-red,  volatile  sublimate.  .Ag  with  Pb 

o.  Blue  flame  and  a  suffocating  pungent  odor. .       S 

(Se,  Te,  Cu  chloride,  and  other  substances  burn 
with  a  blue  flame,  but  the  blue  flame  combined  with 
the  odor  is  distinctive  of  S.) 

p.  Magnetic  residue  left  on  charcoal . .  .Fe,  Ni,  or  Co 

(If  the  assay  is  infusible — does  not  melt — a  mag- 
netic residue  indicates  Fe.) 


II.  TREATMENT  ON  CHARCOAL  WITH  FLUX 

This  test  is  used  when  it  is  desired  to  reduce  a 
salt  to  the  metallic  condition,  so  the  reduction  flame 
is  employed. 

The  substance  to  be  tested  is  finely  pulverized 
and  mixed  thoroughly  with  about  three  times  as 


16  BLOWPIPE  ANALYSIS 

much  powdered  sodium  carbonate  and  a  little 
powdered  borax.  The  mixture  is  then  pressed  into 
a  cake  at  one  end  of  the  charcoal  and  thoroughly 
fused,  beginning  at  the  edges  and  working  toward 
the  center.  A  little  powdered. charcoal  thoroughly 
mixed  with  the  material  to  be  fused  will  often 
facilitate  the  reduction.  If  the  assay  will  not  fuse 
down  to  a  liquid  mass,  either  the  amount  of  flux 
(sodium  carbonate  and  borax)  or  of  heat  applied  is 
deficient.  In  the  latter  case,  raise  the  lamp  wick 
and  trim  off  the  coal  that  forms  upon  it.  It  is 
almost  useless  to  hope  for  satisfactory  results  until 
a  continuous  blast  can  be  blown.  Sometimes  a 
fusion  that  appears  to  have  come  to  a  standstill 
may  be  successfully  completed  by  allowing  the 
assay  to  cool,  removing  the  little  cake  of  semi-fused 
material  with  the  point  of  a  knife,  turning  it  upside 
down  on  the  charcoal,  and  proceeding  as  at  first. 
Some  charcoal  usually  adheres  to  the  upper  surface 
of  the  cake  and  this  has  a  strong  reducing 
influence.  This  process  is  always  necessary  in  the 
case  of  Sn. 

Metallic  Sb  and  many  sulphides  and  arsenides 
yield  metallic  globules  by  this  test,  but  these  are 
distinguishable  by  their  brittleness  from  those 
described  below. 

In  addition  to  sublimates  identical  with  those  that 
form  on  charcoal  without  flux,  other  results  are 
produced  which  may  be  thus  interpreted: 


METHODS  OF  TESTING  17 

a.  White  when  cold,  yellow  when  hot,  light, 

non-volatile  sublimate,  which,  if  moistened 
with  cobalt  nitrate  and  heated,  will  become 
bright  green  when  cold Zn 

(Zn  compounds  which  give  this  test  with  diffi- 
culty or  not  at  all  when  treated  without  flux  will 
give  a  good  color  when  flux  is  used.  The  operation 
should  be  conducted  as  described  under  I.e.  Care 
should  be  exercised  not  to  confuse  the  green  Zn 
coloration  that  appears  in  front  of  the  assay  with 
a  blue  color  on  the  assay  itself.  The  latter  will 
appear  whenever  fusible  material  is  moistened 
with  cobalt  nitrate  and  heated,  regardless  of  the 
presence  or  absence  of  Zn.) 

b.  Lilac  or  lilac-red,  moderately  volatile  subli- 

mate and  a  white,  malleable,  metallic 
button Agwith  Pb 

c.  Yellow   or   orange,    non-volatile    sublimate, 

often  with  a  bluish  white  outer  border, 
deposited  very  close  to  the  assay,  and  a  mal- 
leable, metallic  button,  grayish  white  on  a 
freshly  cut  surface  but  oxidizing  on  expos- 
ure to  the  air Pb 

d.  Yellow   or  orange,   non-volatile   sublimate, 

often  with  a  bluish  white  outer  border, 
deposited  very  close  to  the  assay,  and  a 
rather  brittle,  metallic  button,  grayish  white 
on  a  freshly  cut  surface  but  oxidizing  on 

exposure  to  the  air Bi 

(The  button  may  flatten  somewhat  when  first 
hammered  but  is  not  malleable  like  Pb.  This  will 


18  BLO\YPIP1:  ANALYSIS 

usually  suffice  to  distinguish  between  the  two 
metals,  or  the  test  with  "  bismuth  flux,"  described 
under  I./.,  may  be  applied.) 

e.  White,  malleable,  metallic  button Ag 

(To  distinguish  between  Ag  and  Pb  buttons, 
place  the  button  to  be  tested  in  a  small  depression 
on  a  clean  piece  of  charcoal  and  heat  strongly  in 
the  oxidizing  flame.  If  Pb,  the  characteristic 
yellow  sublimate  will  form,  and,  if  Ag,  there  will  be 
no  coating  or  only  a  faint  brownish  one.  The 
two  metals  may  also  be  distinguished  after  some 
practice  by  the  fact  that  the  Ag  is  decidedly  harder; 
the  flattened  button  may  be  cut  only  with  difficulty 
while  Pb  cuts  easily.) 

/.  White,  malleable,  metallic  buttons  of  small 
size,  which  show  little  or  no  tendency  to 
coalesce  into  one  large  button.  A  white 
when  cold,  yellowish  when  hot,  light,  non- 
volatile sublimate  may  also  form Sn 

(To  distinguish  between  Sn  and  Ag,  remember 
that  the  latter  forms  one  large  button,  usually,  while 
the  many  small  buttons  of  the  former  can  be 
forced  to  coalesce  only  with  great  difficulty  and 
after  prolonged  blowing.  Another  method  of  dis- 
tinguishing them  is  to  alloy  the  button  in  doubt 
with  a  somewhat  smaller  amount  of  Pb,  by  melt- 
ing the  two  together,  and  then  to  note  whether  the 
characteristic  lilac  Ag-Pb  sublimate  is  produced 
in  the  oxidizing  flame.  A  third  method  involves 
an  endeavor  to  secure  the  sublimate  and  cobalt 
nitrate  color  reaction  of  Sn  as  described  under  I.g.) 

g.  Yellow,  malleable,  metallic  button Au 

//.   Red,  malleable,  metallic  mass,  which  it  is 


METHODS  OF  TESTIXG  19 

impossible  to  fuse  into  a  single  button  by 

means  of  the  blowpipe Cu 

i.  Gray,  malleable,  magnetic  particles  (not 
globules) Fe,  Co,  or  Ni 

(The  three  may  be  readily  distinguished  by  the 
"bead  tests"  (V.),q.v.) 

;'.  The  thoroughly  fused  mass  forming  the 
assay,  when  placed  on  a  clean,  moistened 
silver  surface,  produces  a  dark  brown  or 
black  stain S,  Te,  or  Se 

(This  test  is  very  delicate,  but  it  must  be  made 
carefully  in  order  to  succeed.  Exactly  three  parts 
by  volume  of  sodium  carbonate  must  be  used  for 
one  part  of  the  substance  to  be  tested,  and  it  is  best 
to  press  the  fused  mass  with  a  knife  or  hammer- 
head against  the  silver  surface  which  has  previously 
been  moistened  with  a  drop  of  water,  and  to  hold 
it  there  for  a  minute  or  two.  Sometimes  a  slight 
stain  which  may  be  rubbed  off  with  the  fingers  or 
washed  off  with  water  is  produced.  This  should 
be  ignored,  as  the  S,  Te,  or  Se  stain  is  permanent. 

Unless  Te  or  Se  have  been  detected  by  tests 
I/,  l.m.,  lll.c.,  III./.,  III./.,  III.o.,  IV.g.,  or 
IV. k.,  the  presence  of  a  dark  stain  on  the  silver 
may  be  assumed  to  indicate  S.) 

III.  TESTS  IN  CLOSED  TUBES 

It  is  sometimes  desirable  to  treat  the  substance 
just  as  it  is,  while  for  other  tests  it  is  best  to  mix 
it  with  three  or  four  times  as  much  sodium  carbonate 
or  acid  potassium  sulphate.  In  any  case,  the  whole 
charge  should  be  powdered  as  fine  as  possible  and 


20  BLOWPIPE  ANALYSIS 

enough  introduced  within  a  tube  to  fill  it  to  a  height 
of  about  half  an  inch.  This  may  be  done  with  a 
small  paper  or  tin  funnel  or  chute,  or  even  with  a 
very  small  knife  blade. 

The  lower  portion  of  the  tube  and  the  charge 
contained  therein  should  then  be  heated  to  redness 
for  some  time  and  the  results  noted.  An  alcohol 
flame  alone  may  be  used  for  this  purpose,  but  the 
work  may  be  hastened  and  the  results  often  improved 
by  using  the  blowpipe  on  the  alcohol  or  oil  flame. 
Care  must  be  exercised  not  to  use  too  high  a  heat 
or  the  glass  will  melt,  swell,  and  break  open,  or 
will  completely  seal  up  the  charge. 

Possible  results  obtainable  without  flux  are  as 
follows : 

a.  Moisture  in  drops  on  the  walls  of  the  tube  a 

short  distance  above  the  charge H2O 

b.  Liquid,  mirror-like  sublimate  that  collects  in 

globules Hg 

(Only  the  native  metal  will  give  this  result  with- 
out using  sodium  carbonate  flux.) 

c.  Mirror-like  sublimate  of  large  and   small, 

solid,  white  globules Te 

d.  Mirror-like  sublimate  of  very  small,  solid, 

white  globules Cd 

(Cd  and  Te  are  easily  distinguished   by   using 
tests  I./,  and  I.I.) 

e.  Mirror-like,  solid,  black  sublimate,  often  with 

dull  black  sublimate  above,  both  volatile    As 


METHODS  OF  TESTIXG  21 

(A  sulphide  will  not  yield  this  result  without 
using  sodium  carbonate  flux.) 

/.  White  sublimate  composed  of  tiny  globules 
in  a  narrow  zone  immediately  above  the 
charge,  with  a  ring  of  yellow  globules  or 
liquid  at  the  base,  both  very  slowly  vola- 
tile   Te 

(Tests  III.c.  and  III./,  are  given  by  different 
ores  of  Te  or  are  the  result  of  the  application  of  dif- 
ferent temperatures.) 

g.  White,  faint,  very  slowly  volatile  sublimate 
with  a  little  yellow  liquid  close  to  the 
charge • . .  Sb 

(A  sulphide  will  not  yield  this  result  without 
using  sodium  carbonate  flux.) 

h.  Reddish  liquid  when  hot,  yellow  solid  when 
cold;  may  be  almost  white  when  cold  if  the 
amount  is  small S 

*.  Dark  red  liquid  when  hot,  orange  solid  when 

cold As  with  S 

;'.  Black  when  hot,  reddish  brown  when  cold, 

difficultly  volatile  sublimate Sb  with  S 

k.  Black,  volatile  sublimate.  If  the  tube  is 
broken  and  the  sublimate  rubbed  with  a 
cloth,  it  will  sometimes  turn  red,  but  this 
is  unusual Hg  with  S 

/.  Black,  difficultly  volatile  sublimate,  composed 
of  irregularly  shaped  drops,  liquid  when  hot. 
Shades  above  into  a  volatile  sublimate, 


22  BLOWPIPE   ANALYSIS 

reddish  brown  when  hot  and  dark  red  when 
cold Se 

Possible  results  obtainable  with  sodium   carbonate 
flux  are  as  follows: 

m.  Moisture  in  drops  on  the  walls  of  the  tube 

a  short  distance  above  the  charge H2O 

n.  Liquid,   mirror-like  sublimate  that  collects 

in  globules Hg 

o.  Mirror-like   sublimate  of   large  and   small, 

solid,  white  globules Te 

p.  Mirror-like  sublimate  composed  of  very  small, 
solid,  white  globules Cd 

(Cd  and  Te  are  easily  distinguished  by  using 
'rsts  I./,  and  I.I.) 

q.  Mirror-like,  solid,  black  sublimate,  often 
with  a  dull,  solid,  black,  sublimate  above, 
both  volatile As 

r.  White,  faint,  very  slowly  volatile  sublimate 
with  a  little  yellow  liquid  close  to  the 

assay Sb 

Possible    result    obtainable    with    acid    potassium 

sulphate  is  as  follows: 

s.  After  boiling  the  contents  of  the  tube  vigor- 
ously for  several  minutes,  the  glass  immedi- 
ately above  the  charge  is  etched  or  rough- 
ened    F 

(This  result  is  most  easily  recognized  by  breaking 


METHODS  OF   TESTIXG  23 

the  tube,  washing  the  interior  thoroughly,  and 
then  scratching  the  portion  that  may  be  etched 
with  the  point  of  a  knife.  If  etching  has  occurred, 
the  surface  will  feel  much  rougher  than  does 
unetched  glass.) 

IV.  TESTS  IN  OPEN  TUBES 

No  flux  is  used  in  these  tests.  The  substance 
to  be  treated  is  merely  finely  powdered,  a  little  of 
it  is  placed  about  half  an  inch  from  one  end  within 
a  tube,  and  it  is  then  heated  strongly  while  the  tube 
is  held  as  highly  inclined  as  is  possible  without 
losing  the  charge.  The  alcohol  flame  may  be  used, 
but  as  good  or  better  results  are  produced  by  the 
oil  flame  and  the  blowpipe.  In  fact,  the  greater 
heat  of  the  blowpipe-concentrated  oil  flame  is 
essential  for  some  of  the  tests,  and  this  should 
always  be  used  after  securing  negative  results  with 
the  alcohol  flame. 

The  tests  are  very  delicate,  but  are  ordinarily 
used  only  to  corroborate  unsatisfactory  charcoal 
tests. 

Possible  results  may  be  thus  interpreted: 

a.  Moisture  in  drops  on  the  walls  of  the  tube. .  H2O 

b.  Characteristic,  suffocating,  pungent  odor...       S 

c.  White,  light,  very  volatile,  crystalline  subli- 

mate, and  odor  of  garlic As 

d.  White,   heavy  sublimate,   less   volatile  than 


24  BLOWPIPE  ANALYSIS 

that  given  by  As,  and  dense  white  fumes. 
Slender  white  crystals  may  form  on  the 
charge  if  the  heat  is  not  too  great Sb 

e.  White  when  cold  and  light  yellow  when  hot, 
very  heavy,  almost  non-volatile  sublimate 
and  very  dense  white  fumes  which  pass 
along  the  under  side  of  the  tube.  If  a  large 
amount  of  material  be  heated  very  intensely, 
a  little  difficultly  volatile  sublimate,  black 
when  hot  and  reddish  brown  when  cold, 
may  form Sb  with  S 

/.  White,  faint,  non-volatile  sublimate  disc  to 

charge Pb  with  S 

g.  White,  slowly  volatile  sublimate,  which  fuses 
to  globules  which  are  yellow  hot  and  color- 
less cold.  Often,  yellow  globules  form 
around,  and  a  gray  sublimate  collects  above 
the  charge Te 

h.  White,  non -volatile  sublimate,  fusible  to 

yellow  drops,  lighter  when  cool Bi  with  S 

(Bi  with  S  and  Te  are  readily  distinguished  by 
tests  I./,  and  I.;.,  the  latter  being  characteristic  of 
Bi  no  matter  in  what  combinations  it  may  be.) 

i.  White,  delicate  crystals,  yellow  when  hot, 
form  near  and  over  the  charge  after  pro- 
longed heating Mo 

;.  Yellow,  volatile  sublimate,  inclining  toward 
orange  or  red  when  hot,  with  a  very  volatile 


METHODS  OF   TESTING  25 

outer  border  of  white.     Yellow  fumes  and 

odor  of  garlic As  with  S 

(This  result  is  often  produced  when  a  substance 
containing  S  and  As  is  heated  too  rapidly  to  allow 
of  complete  oxidation.) 

k.  Black,  volatile  sublimate  where  very  heavy, 
which  shades  toward  the  upper  end  of  the 
tube  into  a  volatile  coating  that  is  reddish 
brown  when  hot  and  dark  red  when  cold. 
A  curious  and  indescribable  but  character- 
istic odor  and  lilac  fumes,  best  seen  against 
a  black  background Se 

/.  Black,  /ery  volatile  sublimate  with  brownish 
or  iridescent  bands  and  sometimes  a  mirror- 
like  deposit  close  to  the  charge.  White 
fumes,  a  white  volatile  sublimate  beyond 
the  black,  and  characteristic  odor  of  garlic.  As 

(This  result  is  produced  when  a  large  amount 
of  material  is  heated  too  rapidly  to  allow  of  complete 
oxidation.) 

V.  TESTS  WITH  BORAX  BEADS 

The  beads  are  made  by  heating  the  end  of  a 
platinum  wire  to  redness,  dipping  it  into  some 
powdered  or  granulated  borax,  reheating  the  wire 
and  adhering  borax,  and  continuing  the  process 
until  the  bead  when  thoroughly  fused  is  as  large 
as  will  remain  on  the  wire.  If  too  small,  the  color 
is  hard  to  see,  and  a  bead  that  is  too  large  will  keep 


26  BLOWPIPE  ANALYSIS 

falling  from  the  wire.  Some  of  the  oxidizing  flame 
tests  may  be  made  with  the  alcohol  flame,  but  all 
may  be  secured  more  quickly  and  easily  with  the 
oil  flame  and  the  blowpipe. 

The  bead  should  always  be  kept  at  the  end  of 
the  wire,  and  this  may  be  done  by  bending  the  end 
of  the  wire  and  holding  it  in  such  a  manner  that  the 
blowpipe  flame  is  always  directed  against  the  side 
of  the  bead  furthest  from  the  end,  forcing  it  to  the 
end.  A  loop  to  hold  the  bead  should  not  be  formed 
in  the  wire;  it  is  unnecessary  if  the  wire  is  clean,  and 
uses  up  the  platinum  very  rapidly. 

Before  making  any  bead  test,  the  material  to  be 
tested  should  be  powdered  and  thoroughly  roasted 
on  charcoal.  This  is  accomplished  by  spreading 
the  powder  on  the  surface  of  the  charcoal  in  a  flat 
cake,  so  as  to  allow  free  access  of  air,  and  heating 
to  a  dull  red  in  that  part  of  a  small  oxidizing  flame 
that  is  well  outside  of  the  blue  cone.  The  reducing 
flame  should  then  be  applied,  and,  finally,  the 
oxidizing  flame  used  until  no  odors  of  As  or  S  are 
apparent  and  the  assay  ceases  to  burn  with  a  colored 
flame  or  to  volatilize.  Fusion  should  be  prevented 
if  possible.  This  may  be  accomplished  by  mixing 
the  fusible  substance  with  about  an  equal  volume 
of  powdered  charcoal,  which  keeps  the  particles 
separated  and  soon  burns  away.  No  satisfactory 
bead  tests  need  be  expected  from  a  substance  which 
volatilizes  completely  without  solidification. 


METHODS  OF  TESTING  27 

To  make  the  tests,  heat  the  bead  as  hot  as  possible 
and  touch  it  to  a  very  little  (a  few  grains)  of  the 
powdered  substance  to  be  tested.  Some  of  the 
latter  will  adhere  to  the  bead,  which  should  then 
be  heated  in  the  oxidizing  flame  and  any  resulting 
change  of  color  noted.  This  process  should  then 
be  repeated  on  the  same  bead,  using  the  reducing 
flame.  If  the  results  are  negative  or  too  faint  to  be 
decisive,  more  of  the  powder  should  be  dissolved 
in  the  bead  and  the  process  continued  until  a  rela- 
tively large  amount  has  been  added,  when  the  bead 
is  said  to  be  saturated. 

The  colors  of  the  beads  are  due  to  the  presence 
of  oxides  of  the  various  elements,  and  these  oxides 
vary  greatly  in  their  coloring  powers.  In  some 
cases,  deep,  vivid  colors  are  obtained  from  a  few 
grains  of  the  powdered  substance,  while  in  other 
instances  it  is  necessary  to  dip  the  bead  many  times 
into  the  powdered  substance  before  the  character- 
istic colors  are  produced.  Beads  in  the  former  class 
may  be  considered  saturated  when  the  color  is  so 
deep  as  to  make  them  practically  opaque;  those 
in  the  latter  class  are  saturated  when  they  refuse 
to  absorb  more  of  the  material.  This  may  require 
half  a  dozen  applications  of  the  powder. 

In  case  a  bead  becomes  so  saturated  upon  the 
first  application  to  the  powder  that  its  color  is 
indeterminate,  it  may  be  flattened  upon  the  anvil 
while  still  warm  and  the  color  readily  observed  in 


28  BLOWPIPE  AX  A  LYSIS 

the  thin  cake  thus  formed.  This  cake  may  then 
be  broken  into  many  pieces,  and  a  few  of  these 
added  to  a  fresh  bead  without  saturating  the  latter. 
All  beads,  even  when  saturated,  should  be  perfectly 
clear  unless  otherwise  noted.  If  this  is  not  the 
case,  a  higher  heat  should  be  applied  or  new  beads 
formed,  as  a  bead  that  has  been  worked  with  for 
some  time  in  different  flames  is  apt  to  become 
translucent  or  opaque. 

It  should  be  remembered  that  a  bead  containing 
incompletely  roasted  powder  is  very  apt  to  be,  brown 
in  both  flames,  and  then  prolonged  heating  is 
required  to  expel  the  S  or  other  interfering  element 
or  elements. 

The  bead  test  should  never  be  used  on  a  substance 
suspected  to  contain  Cu,  as  that  element  will  alloy 
with  the  platinum  and  give  Cu  beads  whenever 
the  same  wire  is  used  in  subsequent  tests.  Other 
elements  are  apt  to  alloy-  with  the  platinum,  par- 
ticularly during  the  formation  of  reduction  beads, 
and  these  will  make  the  wire  brittle  and  cause  it  to 
break  easily,  but  will  not  interfere  with  tests  made 
before  the  break  occurs. 

To  remove  a  bead  from  the  wire,  either  break 
it  off  on  the  anvil  or  jar  it  off  while  in  a  molten  con- 
dition. When  the  latter  method  is  used,  it  is  a 
good  idea  to  save  the  beads  obtained  from  known 
substances  and  compare  them  with  those  given  by 
unknown  materials. 


METHODS  OF  TESTING  29 

The  most  difficult  operation  involved  in  making 
the  bead  tests  is  the  production  of  a  good,  con- 
tinuous reducing  flame,  yet  this  is  very  im- 
portant and  must  be  mastered.  Manganese  gives 
a  very  highly  colored  bead  in  the  oxidizing  flame, 
and  the  production  of  the  colorless  bead  in  the 
reducing  flame  is  a  good  test  of  ability  in  this  line. 

If  a  substance  contains  two  elements  each  of 
which  yields  a  characteristic  bead,  one  may  so 
modify  the  other  as  to  give  intermediate  results. 
However,  in  most  cases  of  this  kind,  one  color  will 
completely  mask  the  other,  and  this  makes  it  then 
impossible  to  detect  both  elements. 

The  accompanying  table  indicates  the  colors  of 
the  borax  and  salt  of  phosphorus  beads  (see  below) 
yielded  by  the  elements  named  in  both  oxidizing 
and  reducing  flames.  The  following  abbrevia- 
tions are  used:  O.F.  =  oxidizing  flame.  R.F.  = 
reducing  flame.  W  =  warm  bead.  *= saturated 
bead.  C  =  cold  bead. 

As  an  illustration,  consider  iron.  The  table 
shows  that  iron  gives  in  the  oxidizing  flame  a  borax 
bead  that  is  yellow  while  warm  and  colorless  when 
cold  unless  the  bead  is  saturated;  then,  it  is  yellow 
when  cold.  In  the  reducing  flame,  the  bead  is 
green  when  warm  and  colorless  when  cold  unless 
saturated,  when  it  is  bottle-green  when  cold.  Like- 
wise, both  the  non-saturated  and  saturated  salt 
of  phosphorus  beads  are  yellow  when  warm  and 


30 


BLOWPIPE  ANALYSIS 


TABLE   OF 


i 

1 

5: 

*j 

d 

g 

| 

~ 

w 

3 

1 

7- 

g 

•i 

. 

>      - 

^            >              2! 

CQ 

* 

v 

)  P 

C 

we* 

Iron 

tP. 

c 

we* 

Note  i 

)  F 

rr* 

ww* 

Molybdenum 

LF. 

we 

w*c* 

Note  2 

. 

I.F. 

c 

we* 

Titanium 

R.F 

c 

we* 

d. 

OF 

we 

w* 

.,; 

Tungsten 

R.P. 

we 

w* 

< 

e. 

>.F 

c 

we* 

Uranium 

R.F. 

c 

ww* 

c* 

< 

OF 

c 

we* 

Note3 

I 

Vanadium 

R.F. 

we 

g. 

>.P 

w 

cc* 

w* 

Note  4 

Chromium 

R.I'. 

we 

h. 
Copper 

O.F. 

R.F. 

ww* 
w 

CC* 

c 

c* 

Note  5 

. 

OF 

we 

Cobalt 

R.F. 

we 

j. 

O.F. 

we 

Manganese 

R.F 

we 

k 

O  F 

\v\v- 

cc* 

Nickel 

R.F. 

we 

Note  6 

NOTE  i.  Strongly  saturated  bead  is  a  dull  bottle-  or  olive-green  in  the 
reducing  flame  when  cold. 

NOTE  2.     Strongly  saturated  bead  is  opaque  brown  in  the  reducing  name. 

NOTE  .3.  Warm  beads  saturated  and  non-saturated,  are  both  greenish 
yellow  in  the  oxidizing  flame. 

NOTE  4.     Cold,  non-saturated  bead  is  yellowish  green  in  the  oxidizing 

NOTE  s-  Strongly  saturated  bead  is  opaque  and  dark  brownish  red  in  the 
reducing  flame. 


METHODS  Ob'   TEST  IXC, 


31 


BEAD   TESTS 


Colorless. 

l 

c 

J 

PQ 

i 

"5 

d 

i 

VI. 

a. 
Iron 

O.F. 
R.F. 

CC* 
C 

ivw* 

ww* 

c* 

Note  7 

b. 

Titanium 

O.F. 
R.F. 

CC* 

c 

ww* 
ww* 

c* 

Note    8 

c. 
Tungsten 

!    F 

R.F. 

we 
we 

w* 
w* 

C* 

Note  9 

•- 

,1. 
Vanadium 

O.F. 
R.F 

we 

we 

Note  to 

s 

Nickel 

O.F. 
R.F. 

CC* 
CC* 

ww* 
vw* 

f. 

OF 

w 

w*c 

:__ 

Chromium 

R.F. 

we 

: 

OF 

w 

c 

- 
.. 

Uranium 

R.F. 

we 

''• 

h. 
Molybdenum 

O.F. 
R.F 

c 

we* 
we 

N\,tc  i  i 

jCopper 

O.F. 
R.F 

\v\v- 
w 

CC* 

o 

c* 

Note  5 

JCobalt 

O.F 
R.F 

we 
we 

k 

OF 

we 

Manganese 

R.F 

we 

NOTE  6.     Saturated  bead  is  gray  and  opaque  in  the  reducing  flame. 
NOTE  7.     Warm  bead  is  pale  to  deep  yellowish  green  (depending  on  tin 
degree  of  saturation!  in  the  reducing  flame. 

NOTE  8.     Cold,  saturated  bead  is  very  pale  violet  m  the  reducing  flame 
NOTE  o      Cold,  saturated  bead  is  greenish  blue  in  the  reducing  flame. 
NOTE  10.     The  green  reduction  bead  cannot  be  oxidized  to  yellow 
NOTE  ii      Cold,  non-saturated  bead  is  pale  green  in  the  reducing  t 


. 
ng  flame. 


32  BLOWPIPE  ANALYSIS 

colorless  when  cold  in  the  oxidizing  flame,  while  in 
the  reducing  flame  the  non-saturated  salt  of  phos- 
phorous bead  is  pale  yellowish  green  when  warm 
and  colorless  when  cold,  and  the  saturated  bead 
is  deep  yellowish  green  when  warm  and  brown 
when  cold. 

VI.  TESTS  WITH  SALT  OF  PHOSPHORUS  (SODIUM 
AMMONIUM  PHOSPHATE  OR  MICROCOSMIC  SALT) 
BEADS 

These  tests  are  made  in  exactly  the  same  manner 
as  are  those  with  borax  beads  and  the  same  pre- 
cautions should  be  observed.  The  salt  of  phosphorus 
is,  however,  much  more  liquid  than  borax,  especially 
when  first  heated,  and  drops  off  the  wire  very 
easily.  It  will  be  found  necessary  to  build 
the  bead  up  gradually  by  the  addition  of  small 
particles  picked  up  on  the  hot  wire  one  after  the 
other  and  to  use  smaller  beads  than  with  borax. 
If  difficulty  in  retaining  the  bead  is  still  ex- 
perienced, it  will  be  found  advisable  to  form  a 
loop  in  the  end  of  the  wire  by  bending  it  around 
the  point  of  a  lead  pencil.  In  any  case,  it  is  best 
while  forming  the  bead  to  allow  the  flame  to 
play  upon  the  under  side  of  the  fusing  mass,  thus 
buoying  it  upward  and  decreasing  its  tendency  to 
drop  off. 

The  salt  of  phosphorus  tests  are  necessary  for 


METHODS  OF  TESTING  33 

the  recognition  of  some  of  the  elements,  but  in  most 
cases  they  will  be  found  useful  merely  to  corroborate 
unsatisfactory  borax  bead  tests,  and  they  may  often 
be  omitted. 

The  accompanying  table  indicates  the  colors  of 
both  salt  of  phosphorus  and  borax  beads  in  both 
oxidizing  and  reducing  flames.  The  abbreviations 
and  use  of  the  table  have  been  explained  in  the 
discussion  of  the  tests  with  borax  beads. 

VII.  FLAME  TESTS 

When  volatilized,  certain  substances  impart  more 
or  less  decided  colors  to  a  flame,  and  the  recognition 
of  these  colors  constitutes  distinctive  tests  for  such 
elements. 

The  flames  are  best  seen  in  a  dark  room  or  against 
a  dark  background,  and  even  then  it  requires  close 
application  to  perceive  the  very  brief  flashes  of  color 
which  constitute  the  tests  in  many  instances. 

Four  different  methods  of  making  these  tests  may 
be  used,  and  they  should  be  applied  in  the  order 
given,  it  being  unnecessary,  however,  to  seek  further 
results  after  a  determination  has  been  made  by  any 
of  the  methods.  If  two  elements,  both  of  which 
yield  characteristic  flames,  are  present,  one  will 
usually  so  mask  the  other  as  to  make  the  recognition 
of  both  impossible. 

The  second,  third,  or  fourth  method  should 
never  be  used  upon  a  substance  with  a  metallic 


34  BLOWPIPE  ANALYSIS 

lustre  without  a  thorough  preliminary  roasting 
as  As,  Sb,  Pb,  and  other  easily  reduced  elements 
are  apt  to  form  fusible  alloys  with  the  platinum  win 
or  forceps  and  thus  ruin  them. 

Some  elements  yield  their  characteristic  flarm 
colors  best  at  a  low  heat  while  others  requin 
the  highest  heat  available,  so  it  is  always  bes 
to  use  both  low  and  high  temperatures  for  eacl 
test. 

Some  substances  which  ordinarily  yield  no  flami 
tests  may  have  some  of  their  constituents  converter 
into  volatile,  flame-tinting  compounds  by  treatmen 
with  some  reagent,  usually  HCl  or  H2SO4.  In  fact 
it  is  a  safe  practice  always  to  dampen  the  materia 
to  be  tested  with  HCl,  not  even  trying  a  test  withou 
the  use  of  that  acid.  If  no  tinted  flame  results 
H2SO4  should  be  tried. 

First  Method.  Place  a  fragment  or  some  o 
the  powdered  substance  upon  charcoal,  moistei 
with  a  few  drops  of  concentrated  HCl,  and  hea 
in  the  hottest  portion  of  the  blowpipe  flame.  Thi 
only  result  that  need  be  sought  and  noted  (th< 
others  being  more  easily  obtained,  or  the  element: 
being  more  easily  recognized,  by  other  methods)  i: 
the  following: 
a,  Azure-blue  flame,  with  or  without  flashes, 

or  a  border,  of  encrald  green Ci 

(If  this  test  results  favorably,  care  should  be  taken 
not   to    make   the  bead  tests  which   could  only 


METHODS  OF   TESTIXG  35 

yield  Cu,  or  to  heat  the  material  in  the  platinum 
forceps,  since  in  either  of  these  operations  the 
Cu  will  alloy  with  the  Pt  and  ruin  it.) 

Second  Method.  .(This  is  applicable  only  to  car- 
bonates. See  IX.&.)  Seize  a  sliver  of  considerable 
size  in  the.  platinum  forceps,  moisten  it  with  dilute 
HC1  (one  part  of  acid  to  three  or  four  parts  of  water), 
and  hold  the  particle  near  the  base  of  the  flame  of  an 
alcohol  lamp,  the  blowpipe  flame  not  being  used  for 
this  test.  If  the  result  is  negative,  repeat  the  operatipn, 
but  use  the  hot  tip  of  the  alcohol  flame  instead  of 
the  base.  In  a  few  cases,  cold  or  hot  concentrated 
acid  is.  required  and  these  should  be  tried  as  a  last 
resort,  but  the  dilute  acid  should  be  first  tried,  as 
there  are  several  substances  which  will  not  give  a 
good  reaction  with  the  strong  acid. 

The  splinter  should  be  moistened  by  immersing 
it  in  the  acid  and  holding  it  there  until  there  is  a 
vigorous  effervescence  (evolution  of  gas).  Pure, 
fresh  alcohol  and  acids  should  be  used  for  these 
tests,  as  otherwise  a  yellow  Na  flame  is  apt  to  be 
very  prominent  and  may  mask  .the  flames  yielded 
by  Ba  or  Pb. 

If  an  alcohol  lamp  is  not  available,  all  of  the  tests 
described  below  may  be  obtained  by  using  the 
method  next  given,  but  the  results  are  more  vivid 
and  are  easier  obtained  in  the  manner  just  described, 
if  the  substance  tested  is  a  carbonate. 

Possible  results  may  be  thus  interpreted: 


36  BLOWPIPE  ANALYSIS 

b.  Scarlet  flame,  lilac  through  blue  glass Sr 

(A  Li  flame  might  easily  be  confused  with  that 
from  Sr,  but  no  known  Li  carbonate  occurs  in 
nature,  so  this  test  when  obtained  in  the  above 
described  manner  always  indicates  the  presence 
of  Sr.) 

c.  Yellowish  red  flame,  greenish  through  blue 

glass Ca 

(This  is  difficult  to  distinguish  at  first  from  the 
Sr  flame,  but  is  considerably  less  vivid  and  is 
inclined  toward  orange.  It  may  be  positively  identi- 
fied by  the  fact  that  Ca  salts  give  good  tests  no 
matter  whether  dipped  in  concentrated  or  dilute 
acid  and  dilute  acid  must  be  used  to  secure  a  good 
Sr  flame.) 

d.  Yellow  flame Xa 

(This  test  is  too  delicate  to  be  used  with  safety 
unless  very  intense  and  persistent.  Specimens 
that  have  been  handled  will  become  sufficiently 
charged  with  Na  from  the  fingers  to  give  a  good 
flame  test.) 

e.  Yellowish  green  flame,  pale  tint Ba 

(Masked  by  strong  Na  flame.) 
/  Blue  flame,  pale  tint Pb 

(Hot,  concentrated  acid  is  required  for  this  test, 
and  even  then  the  color  will  appear  for  only  an 
instant  when  the  splinter  is  held  in  the  tip  of  the 
flame.) 

Note.  A  vivid  Cu  flame  may  be  obtained  in  this 
manner,  but  this  should  never  be  attempted,  as  the 
forceps  will  thereby  be  ruined. 

Third  Method.     Hold  an  extremely  fine  splinter 


METHODS   OF  TE^TIXG  37 

(as  slender  as  a  very  fine  needle)  in  the  platinum 
forceps,  moisten  it  with  a  drop  of  HC1,  and  introduce 
it  into  the  hottest  part  of  the  blowpipe  flame.  A 
flash  or  a  continuous  appearance  of  color  may  be 
imparted  to  the  flame.  If  the  result  is  negative 
or  unsatisfactory,  remoisten  the  splinter  and  reheat. 
If  this  fails,  repeat  the  operation  with  H2SO4  instead 
of  HC1.  Should  the  splinter  decrepitate,  try  heating 
it  very  slowly,  and,  if  it  still  flies  to  pieces,  the  fourth 
method  must  be  used. 

Possible  results  may  be  thus  interpreted: 

g.  Carmine  flame,  violet  through  blue  glass Li 

/;.  Scarlet  flame,  lilac  through  blue  glass Sr 

(The  colors  of  the  L5  and  Sr  flames  are  so  similar 
that  they  are  easily  confused,  but  they  may  be 
readily  distinguished  by  the  fact  that  a  substance 
that  has  been  ignited  and  has  given  a  Sr  flame  will 
turn  moist  red  litmus  paper  blue  when  crushed 
and  placed  upon  it.  Li  minerals  show  no  effect 
of  this  kind.) 

i.  Yellowish  red  flame,  greenish  through  blue 

glass Ca 

(This  is  difficult  to  distinguish  at  first  from  the 
Sr  or  Li  flames,  but  is  considerably  less  vivid  than 
either  and  is  inclined  toward  orange.) 

;'.  Yellow  flame Na 

(This  test  is  too  delicate  to  be  used  with  safety 
unless  very  intense  and  persistent.  Specimens 
that  have  been  handled  will  become  sufficiently 
charged  with  Na  from  the  fingers  to  give  a  good 
flame  test.) 


38  nWU'Pll'E    AXALYSIS 

k.  Yellowish  green  flame,  pale  tint Ba 

(Masked  by  strong  Na  flame.) 

/.  Bluish  green  flame,  pale  tint P 

(H2SO4  must  be  used  for  this  test  and  the  result 
is  not  usually  very  satisfactory.) 

m.  Bright  green  flame B 

(B  minerals  which  do  not  give  a  flame  test  in 
this  way  should  be  powdered  and  mixed  thoroughly 
with  about  three  volumes  of  a  mixture  of  equal 
parts  of  powdered  acid  potassium  sulphate  and 
calcium  fluoride — fluorite.  This  should  be  intro- 
duced into  the  flame  as  described  in  the  fourth 
method.) 

«.  Blue  flame,  pale  tint Pb 

o.  Blue  flame,  pale  tint Sb 

(The  reducing  flame  must  be  used  to  obtain 
this  result,  which  is  neither  very  satisfactory  nor 
determinative.  Care  should  be  taken  not  to  test 
an  Sb  ore  in  this  way,  as  it  is  apt  to  alloy  with,  and 
ruin,  the  platinum  forceps.) 

p.  Violet  flame,  violet  through  blue  glass K 

(This  is  difficult  to  obtain  in  most  cases  and 
is  entirely  masked  by  a  pale  Na  flame.  The  latter 
is,  however,  entirely  absorbed  by  blue  glass,  which 
transmits  the  K  flame  as  of  lilac  or  violet  color, 
depending  upon  the  shade  of  the  glass.) 

Note.  A  vivid  Cu  flame  may  be  obtained  in  this 
manner,  but  this  should  never  be  attempted,  as  the 
forceps  will  thereby  be  ruined. 

Fourth  Method.  Powder  the  material  to  be 
tested  very  fine,  pick  up  a  little  of  this  powder  upon 


METHODS  OF   TESTING  39 

a,  flattened  platinum  wire  moistened  with  HC1, 
and  introduce  the  powder-coated  wire  into  the 
hottest  part  of  the  blowpipe  flame.  Momentary 
flashes  or  continuous  appearances  of  color  may  be 
imparted  to  the  flame,  which  are  to  be  interpreted 
as  under  the  third  method.  If  the  results  are  nega- 
tive, repeat  the  operation,  using  H2SO4  instead  of 
HC1. 

This  method  is  not  usually  very  satisfactory  and 
should  not  be  used  unless  it  is  impossible  to  obtain 
a  splinter  fine  enough  to  be  tested  by  the  third 
method.  Minerals  which  decrepitate  badly,  which 
are  very  soft,  or  which  occur  as  a  powder  must,  of 
course,  be  tested  by  this  last  method. 

VIII.  COBALT  NITRATE  COLORATION  TESTS 

To  make  these  tests,  hold  a  small  splinter  of  the 
substance  to  be  tested  in  the  platinum  forceps  and 
heat  it  in  the  blowpipe  flame  to  the  highest  possible 
temperature.  Then  examine  it  with  a  lens;  if  it 
shows  any  signs  of  fusion,  this  test  cannot  be  applied. 
If  non-fusible,  moisten  it  with  cobalt  nitrate  and 
ignite  strongly  in  the  hottest  part  of  the  blowpipe 
flame.  It  will  first  turn  black  but  after  prolonged 
heating  may  assume  a  characteristic  tint.  If  a 
splinter  of  the  substance  cannot  be  obtained,  it 
should  be  powdered  and  the  test  conducted  upon 
a  flat  cake  of  the  powder  upon  charcoal.  Longer 


40  BLOWPIPE  AXALYSIS 

heating  is  required  by  this  method,  however,  and 
the  results  are  not  apt  to  be  as  satisfactory. 

This  test  can  be  applied  only  to  non-fusible, 
white  or  faintly  tinted  minerals,  or  those  which 
become  white  or  faintly  tinted  upon  ignition. 

Possible  results  may  be  thus  interpreted: 

a.  Plue  coloration Al  or  Zn  silicate 

(Al  minerals  and  Zn  silicate  give  identical  results 
by  this  test.  If  Zn  has  been  obtained  by  tests  I.e., 
or  II. a.,  it  is  impossible  to  test  for  Al  in  this 
way.  If  Zn  is  not  present,  this  test  may  be  inter- 
preted as  indicating  the  presence  of  Al.  Occa- 
sionally a  little  green  forms  with  the  blue  on  Zn 
silicates,  which  never  happens  in  the  case  of  Al  min- 
erals.) 

b.  Green  coloration,  dark Sb 

c.  Green  coloration,  bright  tint,  best  seen  when 

cold Zn 

d.  Pinkish  or  flesh-tint  coloration Mg 

IX.  TESTS  WITH  ACIDS 

These  are  really  purely  chemical  and  should  not 
be  included  under  blowpipe  analysis,  but  two 
are  so  simple  and  useful  that  they  are  given  below. 

a.  The  finely  powdered  material,  when  boiled 

almost    to   dryness   in  concentrated  nitric 
acid,  yields  a  gelatinous  mass a  silicate 

b.  The  powdered  material  effervesces  vigorously 


METHODS  OF  TEST1XG  41 

when  placed  in  a  test-tube  containing  some 
condition  of  hydrochloric  acid a  carbonate 

(In  some  cases  the  tests  appear  in  cold,  dilute 
acid,  while,  in  other  instances,  hot  dilute,  cold  con- 
centrated, or  hot  concentrated  may  be  required. 
It  is  best  to  experiment  with  the  dilute  acid  first, 
and  then,  if  results  are  negative,  to  increase  the 
temperature  until  all  conditions  of  acid  have  been 
tried. 

It  is  not  always  necessary  to  powder  the  material 
to  be  tested,  but  this  is  sometimes  required  and 
never  does  any  harm. 

Care  should  be  taken  not  to  confuse  effervescence 
(escape  of  CO2)  with  boiling  (escape  of  steam) 
when  boiling  acid  is  used. 

Some  sulphides  may  effervesce  in  hydrochloric 
acid,  but  these  may  be  distinguished  from  carbon- 
ates by  the  fact  that  they  yield  a  gas  (H2S)  that 
smells  like  bad  eggs.) 


CHAPTER  III 


NK   I  <>R  OrALlTATIYK  BLOWPJPK 
ANALYSIS 

BLOWPIPE  analysis  is  ordinarily  used  for  the  pur- 
pose of  ascertaining  what  elements  an  unknown 
substance  contains,  this  process  being  known  in 
chemistry  as  qualitative  analysis.  It  is  not  possible, 
excepting  in  a  few  cases  and  by  the  application  of 
very  refined  methods  not  here  discussed,  to  deter- 
mine how  much  of  an  element  is  present  —  to  make 
a  quantitative  analysis  of  the  substance,  but,  if  the 
elements  present  are  known,  it  is  usually  possible 
to  determine  the  nature  of  the  substance  by  applying 
the  principles  set'  forth  in  Chapter  IV.  Where  the 
nature  of  a  mineral  has  thus  been  determined,  it  is 
comparatively  easy  to  compute  the  percentage  com- 
position with  considerable  accuracy  in  many  cases, 
by  applying  the  principles  presented  in  Chapter 
VI,  A  tabulation  of  the  principal  elements  present 
in  many  common  minerals  are  given  in  Chap 
ter  V.  Even  when  the  name  and  nature  of 
the  mineral  cannot  be  ascertained  by  blowpipe 
methods,  the  ability  to  ascertain  the  commercially 
important  elements  that  it  contains  is  often  of  the 

42 


QUALITATIVE  BLOWPIPE  ANALYSIS  43 

greatest  value,  since  it  is  then  possible  to  decide 
whether  it  is  worth  while  to  procure  a  chemical 
analysis  or  an  assay  of  the  substance. 

The  following  scheme  has  been  devised  as  a  guide 
for  making  a  complete  qualitative  analysis  of  an 
unknown  substance  with  the  greatest  economy  of 
time  and  labor.  It  should  not  be  expected  that 
every  mineral  containing  As,  for  instance,  will  yield 
every  test  for  As  mentioned  in  Chapter  II  or  in  the 
following  outline,  but  in  most  cases  the  mineral 
will  give  one  or  more  of  the  tests  there  given.  It 
is  poor  practice  to  assume  that  a  mineral  contains 
a  certain  element  and  then  test  for  that  element, 
repeating  the  operation  for  other  elements.  A  far 
better  plan  is  to  follow  the  outline  rigidly  and  to 
draw  conclusions  from  the  results  secured.  This 
saves  time  and  makes  it  impossible  to  forget  to  try 
tests. 

If  it  is  suspected  that  Hg  is  present  in  a  substance, 
it  should  be  tested  only  in  the  closed  tube  (see 
III.6.))  as  the  vapors  are  very  poisonous. 

OUTLINE 

A.  Powder  material  very  fine  and  place  upon  char- 
coal, pressing  out  with  a  knife-blade  into  a 
flat  cake.     Moisten  with  water  if  necessary  to 
keep  the  charge  from  flying  off  the  charcoal, 
i.  Test  for  As,  Sb,  Sb  with  As,  Mo,  Te,  As  with 


44  BLOWPIPE  AX.lLVSfS 

S,  Pb,  Bi,  Cd,  Sc,  Ag  with  Pb,  and  S. 
(Seel.) 

2.  Test  for  Fe.     (See  I. p.) 

Separate  the  residue  from  the  above  tests 
into  two  portions  and  save  one  of  these  for  a 
later  test.  On  the  portion  still  remaining  on  the 
charcoal  make: 

3.  Test  for  Zn  and  Sn.     (See  I.e.  and  I.g.) 

4.  Test  for  Cu  on  residue  from  A-3-      (See  VII. a.) 

5.  Test  for  Al,  Mg,  Zn,  Sb,  and  Zn  silicate  on 
residue  from  A.4.     (See  VIII.) 

(This  test  can  be  made  only  upon  light  colored, 
infusible  material,  and  need  not  be  tried  if  Zn  has 
already  been  found.) 

B.  If  A.4.  gave  no  Cu  flame  (if  Cu  is  present  it  is 

useless  to  make  the  following  tests)  make  borax 
and  salt  of  phosphorus  bead  tests  for  the  ele- 
ments named  below,  using  the  residue  saved 
from  A.  2. 

i.  Test  for  Fe,  Mo,  Ti,  W,  U,  V,    Cr,  Cu,  Co, 
Mn,  and  Ni.     (See  V.  and  VI.) 

C.  In  case  A.I.  gave  a  result  that  might  be  inter- 

preted as  indicating  either  Pb  or  Bi,  use  the 
bismuth  flux  test  to  distinguish  them, 
i.  Test  for  Bi  on  some  of  the  original  material, 
using  bismuth  flux.     (See  I./.) 

D.  If  A.4.  gave  no  Cu  flame  (if  Cu  is  present  it  is 

useless  to  make  the  following  tests),  hold  a 
piece  of  the  original  material  as  large  as  a  tooth- 


QUALITATIVE  BLOWPIPE  ANALYSIS  45 

pick  or  match  in  the  platinum  forceps  and 
make  the  flame  tests  as  described  under  VII., 
Second  Method. 

1.  Test  for  Sr,  Ca,  Na,  Ba,  and  Pb  carbonates. 
(See  VII.,  Second  Method.) 

If  no  satisfactory  results  are  obtained  from 
D.I.,  make  the  flame  tests  as  described  under 
VII.,  Third  Method. 

2.  Test  for  Li,  Sr,  Ca,  Na,  Ba,  P,  B,  Pb,  Sb, 
and  K.     (See  VII. ,  Third  Method.) 

If  no  satisfactory  results  are  obtained  from 
D.2.,  make  the  flame  tests  as  described  under 
VII. ,  Fourth  Method. 

3.  Test  for  Li,  Sr,  Ca,  Na,  Ba,  P,  B,  Pb,  Sb,  and 
K.     (See  VII.,  Third  Method.) 

E.  On   some  of  the  original   material,   powdered, 
make  the  closed  tube  tests  without  flux. 

1.  Test  for  H2O,  Hg,  Te,  Cd,  As,  Sb,  S,  As  with 
S,  Sb  with  S,  Hg  with  S,  and  Se.     (See  IH.a. 
to/.) 

On  some  of  the  original  material,  powdered, 
make  the  closed,  tube  tests  with  flux,  provided 
E.I.  has  not  yielded  determinative  results. 

2.  Test  for  H2O,  Hg,  Te,  Cd,  As,  and  Sb.     (See 
Ill.m.  to  r.) 

On  some  of  the  original  material,  powdered, 
make  the  closed  tube  test  with  acid  potassium 
sulphate. 


46  BLOWPIPE  ANALYSIS 

3.  Test  for  F.     (See  lll.s.) 

F.  On   some  of  the  original   material,   powdered, 

make  the  open  tube  tests. 

i.  Test  for  H2O,  S,  As,  Sb,  Sb  with  S,  Pb  with 
S,  Te,  Bi  with  S,  Mo,  As  with  S,  and  Se. 
(See  IV.) 

Note.  It  is  always  well  to  make  tests  E.  and  F. 
even  when  A.  has  given  determinative  results,  as 
several  of  the  elements  determined  by  means  of 
tests  E.  and  F.  may  fail  to  show  in  test  A.  It  is 
a  good  practice  to  corroborate  results  obtained  by 
test  A.  by  means  of  tests  E  and  F. 

G.  On  some  of  the  original  material,  powdered, 

make  the  tests  on  charcoal  with  flux. 

1.  Test  for  Zn,  Ag  with  Pb,  Pb,  Bi,  Ag,  Sn,  Au, 
Cu,  and  Fe,  Co,  or  Ni.     (See  II.) 

On  the  residue  from  G.I.,  make  the  silver 
test  for  S,  Te,  or  Se,  provided  these  elements, 
or  one  of  them,  have  not  already  been  detected 
by  other  tests. 

2.  Test  for  S,  Te,  or  Se.  '  (See  II.;.) 

H,  On  some  of  the  original  material,   powdered, 
make  the  tests  with  acids  in  test-tubes. 

1.  Test  for  a  silicate  with  nitric  acid.     (See  IX.c.) 

2.  Test  for  a  carbonate  with  hydrochloric  acid. 
(SeeIX.6.) 


CHAPTER  IV 

IXDKX  TO  ALL  OF  THE  TESTS  YIELDED  BY 
THE  VARIOUS  ELEMENTS 

IT  is  the  purpose  of  this  index  to  furnish  a  complete 
list  of  all  the  blowpipe  tests  for  any  element  dis- 
cussed in  the  preceding  pages.  It  will  be  found 
useful  where  the  interest  is  concentrated  upon  one  or 
two  elements  to  the  exclusion  of  all  others,  but  should 
not  be  used  in  making  a  complete  qualitative  blow- 
pipe analysis  of  a  substance.  It  should  not  be 
expected,  that  any  mineral  will  necessarily  yield  all 
of  the  tests  for  each  of  the  constituents. 

The  references  are  to  the  tests  described  in 
Chapter  II,  and  a  page  index  of  these  tests  is  here 
given : 

PAQB 

I.  Treatment  on  Charcoal  without  Flux . .  i  o 

II.  Treatment  on  Charcoal  with  Flux 15 

III.  Tests  in  Closed  Tubes 19 

IV.  Tests  in  Open  Tubes 23 

V.  Tests  with  Borax  Beads 25 

VI.  Tests  with  Salt  of  Phosphorus  Beads. .  32 

VII.  Flame  Tests 33 

VIII.  Cobalt  Nitrate  Coloration  Tests 39 

IX.  Tests  with  Acids 40 

47 


48  BLOWPIPE  ANALYSIS 

Aluminum:  VIII.,a. 

Antimony:    l.b.,    I.e.,  Hl.g.,    III./.,    IILr.,    IV.d., 

IVe.,  VII.o.,  and  VIII.6. 
Arsenic:  I. a.,  I.e.,  I.h.,   I.k.,    Ill.e.,    lll.i.,   lll.q., 

IV.c.,  IV.;.,  and  IYJ. 
Barium:  Vll.e.,  and  VII.*. 
Bismuth:  I.;.,  II.d.,  and  IV.A. 
Boron:  Vll.m. 

Cadmium:  I/.,  II W.,  and  III.^. 
Calcium:  VII.c.,  and  VII./. 
Chromium:  V.g.,  and  VL/. 
Cobalt:  I.p.,  II.*.,  V.i.,  and  VI. j. 
Copper:    ll.h.,  V.h.,  VI.*.,  and  Vll.a. 
Fluorine:  III.s. 
Gold:  II.g. 

Iron:  !./>.,  Il.f,.  V.a.,  and  VLa. 
Lead:    I.i.,   !.».,    II &,    II.c.,    IV./.,    VII./.,    and 

Vll.n. 

Lithium:  VII.^. 
Magnesium:  VIII. d. 
Manganese:  V.;.,  and  VL*. 
Mercury:  III.&.,  III.*.,  and  III.w. 
Molybdenum:  l.d.t  IV.*.,  V.b.,  and  VI.h. 
Nickel:  I.p.,  II.*.,  V.*.,  and  VI.e. 
Phosphorus:  VIIJ. 
Potassium:  VII.p. 

Selenium:  I.m.,  II.;.,- III./.,  and  IV.*. 
Silver:  !.».,  H.&.,  and  Il.e. 
Sodium:  Vll.d.,  and  VII./. 


TESTS  YIELDED  BY   VARIOUS  ELEMENTS      49 

Strontium:  VII.6.,  and  VILA. 

Sulphur:  LA.,  I.e.,  II./.,  III.A.,  III.*.,  III./.,  III.*., 

IV.6.,  IV.e.,  IV./,  IV.A.,  and  IV./. 
Tellurium:     I./.,    II.;.,    IILc.,    III./.,    III.o.,  and 


Tin:  I*.,  and  II./. 
Titanium:  V.c.,  and  VI.6. 
Tungsten:  V.d.,  and  VI.c. 
Uranium:  V.e.,  and  Vl.g. 
Vanadium:  V./.,  and  Vl.d. 
Zinc:  I.e.,  ILa.,  VIILa.,  and  VIII.c. 
Water:  IILa.,  Ill.m.,  and  IV.a. 
A  silicate:  IX.a. 
A  carbonate:  IX.6. 


CHAPTER  V 

THE  DETERMINATION  OI    MINERALS  BY 
MEANS  OF  THE  BLOWPIPE 

WHILE  the  determination  of  the  constituent  ele- 
ments of  a  mineral  is  the  usual  aim  of  a  blowpipe 
analysis,  it  is  often  desirable  to  be  able  to  assign 
the  correct  mineralogical  name  to  the  substance, 
since,  when  this  can  be  done,  it  is  frequently  possible 
to  determine  its  percentage  composition  with  con- 
siderable accuracy.  It  is  not,  unfortunately,  possible 
in  many  cases  to  determine  a  mineral  by  blowpipe 
tests  alone;  these  must  be  considered  in  connection 
with  the  physical  characteristics  before  a  reliable 
decision  as  to  the  correct  name  can  be  safely  made. 
There  are,  however,  a  considerable  number  of 
minerals  with  unique  groups  of  constituents  which 
may  be  determined  by  blowpipe  analyses,  and  it 
is  hoped  that  the  following  table  will  prove  useful 
in  this  respect.  It  includes  most  of  the  important 
ores  and  some  of  lesser  importance,  as  well  as  a 
number  of  gangue  minerals,  but  some  very  important 
ores  are  omitted  as  well  as  a  great  number  of  common 
minerals  for  the  reason  that  blowpipe  tests  arc 
little  or  no  aid  in  their  recognition.  In  a  large 

,50 


DETERMINATION  OF  MINERALS  51 

number  of  cases  two  or  more  minerals  on  this  table 
yield  tests  for  identically  the  same  elements.  Such 
substances  can  be  readily  distinguished  by  their 
appearance  or  by  simple  physical  tests.  For  this 
purpose  almost  any  book  on  mineralogy  will  answer, 
but  the  author  naturally  prefers  his  own  work, 
A  Pocket  Handbook  of  Minerals,  published  by 
John  Wiley  &  Sons,  New  York,  which  places  all 
the  emphasis  upon  the  physical  distinctions. 

In  the  following  table  the  chemical  formula  is 
placed  in  parentheses  after  the  name  of  each  min- 
eral. By  applying  the  principles  presented  in 
Chapter  VI  it  should  be  a  comparatively  simple 
matter  to^  compute  the  percentage  of  any  or  all 
elements  present  in  any  mineral  of  fixed  composition. 
The  letters  to  the  left  of  each  name  are  the  symbols 
of  the  elements  that  may  be  found  by  means  of  the 
blowpipe;  in  comparatively  few  cases  do  they  con- 
stitute all  the  elements  present  in  the  mineral  before 
which  they  stand,  but  the  remainder  fail  to  give 
satisfactory  tests  with  the  blowpipe. 

The  name  of  a  mineral  is  repeated  under  each 
element  for  which  it  yields  blowpipe  tests.     Water 
(H2O)  is  treated  as  an  element. 
Aluminum. 

Al— Corundum  (A12O3) 

Al,  Li— Spodumene  (LiAlSi2OG). 

Al,  P,  H2O— Turquois  ( A1PO.,.A1(OH)3+H2O 
+  Cu). 


52  BLOWPIPE  ANALYSIS 

» 

^  Al,  K— Orthoclase  (KAlSiaO8). 

Al,S,H20-Alunite(K2SO4.3Al2O3.3SO3.6H2O). 
Al,  H2O— Bauxite  (A12O3  +  2H2O). 
Al,  H2O— Kaolin  (Al2Si2O7  +  2H2O). 

Antimony. 

Sb — Native  Antimony  (Sb). 

Sb— Cervantite  (Sb2O4). 

Sb,  As— Allemontite  (SbAs). 
^  Sb,  Cu,  S— Tetrahedrite  (Cu8Sb2S7). 

Sb,  Pb,  S— Jamesonite  (Pb2Sb2S5). 

Sb,  Ag,  S— Pyrargyrite  (AggSbSa). 

Sb,  Ag,  S— Stephanite  (Ag5SbS4). 
u  Sb,  S— Stibnite  (Sb2S3). 

Arsenic. 

As — Native  Arsenic  (As). 
As,  Sb— Allemontite  (AsSb). 
As,  Co— Smaltite  ((Co,Ni)  As2). 
i-  As,  Co,  S— Cobaltite  (CoAsS). 
As,  Cu,  S— Tennantite  (Cu8As2S7). 
As,  Cu,  S— Enargite  (Cu3AsS4). 
As,  Cu,  H2O— Olivenite  (Cu4As2O9+H2O). 
As,  Cu,  H2O— Conichalcite    ((Cu,Ca)4As2O9-f 

3/2H20). 

As,  Fe— Lollingite  (FeAs2). 
As,  Fe,  S— Arsenopyrite    (FeAsS). 
As,  Ni— Niccolite  (NiAs). 
As,  Pb— Mimetite  (PbCl2.3Pb3As2O8.). 
As,  Ag,  S— Proustite  (Ag-jAsSg). 


DETERMINATION  OF  MINERALS  53 

As,  S— Realgar  (As2S2). 
As,  S — Orpiment  (As2S3). 

Barium. 

Ba— Witherite  (BaCO3). 
Ba,  S— Barite  (BaSO4). 

Bismuth. 

Bi— Native  Bismuth  (Bi). 

Bi— Bismite  (Bi2O3). 

Bi,  S— Bismuthinite  (Bi2S3). 

Bi,  Te— Tetradymite  (TeBi). 

Bi,  H2O— Bismutite  (Bi2CO5  +  H2O). 

Boron. 

B— Boracite   (Mg7Cl2B1GO3o). 

B,  Na,  H2O— Borax  (Na2B4O74-ioH2O). 

B,  H2O— Colemanite  (Ca2B6Oii+5H2O). 

Cadmium. 

Cd,  S— Greenockite  (CdS). 

Calcium. 

Ca— Calcite  (CaCO3). 

Ca,  F— Fluorite  (CaF2). 

Ca,  Mg— Dolomite  ((Ca,  Mg)  CO3). 

Ca,  P— Apatite  (Ca  (Cl,  F)2.3Ca3P2O8). 

Ca,  S— Anhydrite  (CaSO4). 

Ca,  S,  H2O— Gypsum  (CaSO4  +  2H2O). 
Chromium. 

Cr,  Fe— Chromite  (FeCr2O4). 

Cr,  Pb— Crocoite  (PbCrO4). 


54  BLOW PIPI-:  ANALYSIS 

Cobalt. 

Co,  As— Smaltite  ((Co,  Ni)  As2). 
Co,  As,  S— Cobaltite  (CoAsS). 

Copper 

Cu— Native  Copper  (Cu). 

Cu— Cuprite  (Cu2O). 

Cu— Tenorite  (CuO). 

Cu— Atacamite  (CuCl2.3Cu(OH)2). 

Cu,  Sb,  S— Tetrahedrite  (Cu8Sb2S7). 

Cu,  As,  S— Tennantite  (Cu8As2S7). 

Cu,  As,  S— Enargite  (Cu3AsS4). 

Cu,  As,  H2O— Olivenite  (Cu4As2O9+H2O). 

Cu,  As,  H2O— Conichalcite  ((Cu,  Ca)4As2O9  + 

3/2H20). 

Cu,  Fe,  S— Bornite  (Cu5FeS4). 
Cu,  Fe,S— Chalcopyrite  (CuFeS2). 
Cu,  S— Chalcocite  (Cu2S). 
Cu,  S— Covellite  (CuS). 
Cu,  S,  H2O— Chalcanthite  (CuSO4  +  5HL>O). 
Cu,  H2O— Malachite   (Cu2CO4  +  H2O). 
Cu,H2O— Azurite  (Cu3C2O7  +  H2O). 
Cu,  H2O— Chrysocolla  (CuSiO3  +  2H2O). 

Fluorine. 

F,  Ca— Fluorite  (CaF2). 
F,  Na— Cryolite  (Na3AlF6). 

Gold. 

An — Native  Gold  (Au,. 
Au,  Te— Calaverite  (AuTe2). 


DETERMINATION  OF  MINERALS 

Iron. 

*•  Fe— Hematite  (Fe2O3). 
*-   Fe — Magnetite  (Fe3O4). 
Fe— Siderite  (FeCO3). 
Fc,  As— Lollingite  (FeAs2). 
Fe,  As,  S — Arsenopyrite  (FeAsS). 
Fe,  Cr— Chromite  (FeCr2O4). 
.    Fe,  Mn,  Zn— Franklinite  ((Fe,  Zn,  Mn)3O4). 
Fe,  P,  H2O— Vivianite  (Fe3P2O8-f-8H2O). 
Fe,  S— Pyrrhotite  (FenSn  +  I). 
Fe,  S— Pyrite  (FeS2). 
Fe,  Ti— Ilmenite  (FeTiO3). 
Fe,  H2O— Limonite  (2Fe2O3  +  3H2O). 

Lead. 

Pb— Cerussite  (PbCO3). 
Pb,  Sb,  S— Jamesonite  (Pb2Sb2S5). 
Pb,  As— Mimetite    (PbCl2.3Pb3As2O8.). 
Pb,  Cr— Crocoite  (PbCrO4). 
^  Pb,  Mo— Wulfenite  (PbMoO4). 
Pb,  P— Pyromorphite  (PbCl2.3Pb3P2O8). 
Pb,  S— Galenite  (PbS). 
Pb,  S— Anglesite  (PbSO4). 
Pb,  V— Vanadinite  (PbCl2.3Pb3V2O8). 
Pb,  V,  etc. — Uraninite  (?). 

Lithium. 

Li,  Al— Spodumene  (LiAlSi2O6). 

Magnesium 

Mg— Magnesite  (MgCO3). 


56  BLOWPIPE  AXALYSIS 

Mg,  Ca— Dolomite  ((Mg,  Ca)CO3). 
Mg,  H20— Talc  (MgaSi.On+HoO). 

Manganese. 

Mn— Pyrolusite  (MnO2). 

Mn— Rhodochrosite  (MnCO3). 

Mn— Rhodonite  (MnSiO3). 

Mn,  Fe,  Zn— Franklinite  ( (Mn,  Fe,  Zn)3O4). 

Mn,  S— Alabandite  (MnS). 

Mn,  H2O— Manganite  (Mn2O3  +  H2O). 

Mn,   H2O— Psilomelane    (MnO2  +  2H2O). 

Mercury. 

Hg — Native  Mercury  (Hg). 
Hg,  S— Cinnabar  (HgS). 

Molybdenum. 

Mo— Molybdite  (MoO3). 

Mo,  Pb— Wulfenite  (PbMoO4). 

Mo,  S— Molybdenite  (MoS2). 

Nickel. 

Ni,  As— Niccolite  (NiAs). 

Ni,  S— Millerite  (NiS). 

Ni,  H20— Garnierite  (H2(Ni,  Mg)SiO4  +  H2O). 

Phosphorus. 

P,    Al,    H2O— Turquois       (A1PO4.A1(OH)3  + 

H2O  +  Cu). 

P,  Ca— Apatite  (Ca(Cl,  F)2.3Ca3P2O8). 
P,  Fe,  H2O— Vivianite    (Fe3P2O8  +  8H2O). 
P,  Pb— Pyromorphite  (PbCl2.3Pb3P2O8). 


DETERMINAT1OX   OF  MINERALS  57 

Potassium. 

K— Sylvite  (KC1). 

K,  Al— Orthoclase  (KAlSi3O8). 

Selenium. 

Se,  Pb— Clausthalite  (PbSe). 

Silver. 

Ag — Native  Silver  (Ag). 
Ag— Cerargyrite  (AgCl). 
Ag,  Sb,  S — Pyrargyrite  (AgsSbS3). 
Ag,  Sb,  S— Stephanite  (Ag5SbS4). 
Ag,  As,  S— Proustite  (Ag3AsS3). 
Ag,  Te— Petzite  ((Ag,  Au)2Te). 
Ag,  Te— Sylvanite  ( (Ag,  Au)Te2). 
Ag,  S— Argentite  (AgzS). 
Ag,  Te— Hessite  (Ag^e). 

Sodium 

Na— Halite  (NaCl). 

Na,  B,  H2O— Borax  (Na2B4O7  +  ioH2O). 

Na,  F— Cryolite  (Na3AlF6). 

Na,  S— Thenardite  (Na2SO4). 

Na,  H2O— Natron  (Na2CO3  +  ioH2O). 

Na,  H2O—Trona  (Na2CO3.HNaCO3+2H2O). 

Strontium 

Sr— Strontianite  (SrCO3). 
Sr,  S— Celestite  (SrSO4). 


58  BLOWPIPE  ANALYSIS 

Sulphur. 

S— Native  Sulphur  (S). 

S,Al,H2O-Alunite(K2S04.3Al203.3S03.6H2O). 
'  S,  Sb— Stibnite  (Sb2S3). 
-  S,  Sb,  Cu— Tetrahedrite  (Cu8Sb>S7). 

S,  Sb,  Pb— Jamesonite  (Pb2Sb2S.-,). 

S,  Sb,  Ag— Pyrargyritc  (AgsSbS3). 

S,  As— Realgar  (As2S2). 
t-S,  As — Orpiment  (As2S3). 

S,  As,  Cu— Tennantite  (Cu8As2S7). 

S,  As,  Cu— Enargite  (Cu3AsS4). 

S,  As,  Fe — Arsenopyrite  (FeAsS). 

S,  As,  Ag— Proustite  (AgsAsSs). 
-S,Ba— Barite  (BaSO4). 

S,  Bi— Bismuthinite  (Bi2S3). 

S,  Cd— Greenockite  (CdS). 

S,  Ca— Anhydrite  (CaSO4). 

S,  Ca,  H2O— Gypsum  (CaSO4  +  2H2O). 

S,  Cu— Chalcocite  (Cu2S). 

S,  Cu— Covellite  (CuS). 

S,  Cu,  Fe— Bornite  (Cu5FeS4). 
-  S,  Cu,  Fe— Chalcopyrite  (CuFeS2). 

S,  Cu,  H2O— Chalcanthite 
^S,  Fe— Pyrrhotite  (FenSn+i). 
-S,  Fe— Pyrite  (FeS2). 
.  S,  Pb— Galenite  (PbS). 

S,  Pb— Anglesite  (PbSO4). 

S,  Mn— Alabandite  (MnS). 
-S,  Mo— Molybdenite  (MoS2). 


DETERMINATION  OF  MINERALS  59 

S,Ni— Millerite(NiS). 

S,  Ag— Argentite  (A&S). 

S,  Na— Thenardite  (Na2SO4). 
*S,  Sr— Celestite  (SrSO4). 
•  S,  Zn— Sphalerite  (ZnS). 

Tellurium. 

Te— Native  Tellurium  (Te). 
Te,  Bi— Tetradymite  (BiTe). 
Te,  An— Gala verite  (AuTe2). 
Te,  Ag— Petzite  ((Au,  Ag)2Te). 
Te,  Ag— Sylvanite  ((Au,  Ag)Te2). 

Tin. 
-    Sn— Cassiterite   (SnO2). 

Titanium. 
-    Ti— Rutile  (TiO2). 

Ti— Titanite  (CaTiSiO6). 
Ti,  Fe— Ilmenite  (TeTiO3). 

Tungsten. 

W—  Scheelite  (CaWO4). 

Uranium. 

I",  Pb,  etc.— Uraninite  (?). 

Vanadium. 

V.  Pb— Yanadinite  (Pb 

Zinc. 

Zn — Zincite  (ZnO). 
••  Zn— Smithsonite  (ZnCO3). 


60  BLOWPIPE  AXALVSIS 

Zn— Willemite  (Zn2SiO4). 

Zn,  Fe,  Mn— Franklinite  ((Zn,  Fe,  Mn)3O4). 

Zn,  S— Sphalerite  (ZnS). 

Zn,  H2O— Hydrozincite  foZnCOg  +  2H2O). 

Zn,  H2O— Calamine  (Zn2SiO4  +  H2O). 
Water. 

H2O,  Al— Bauxite    (A12O3  +  2H2O). 

H20,  Al— Kaolin  (Al2Si2O7  +  2H2O). 

H2O,A1,P— Turquois(AlPO4.Al(OH)3+H2O  + 
Cu). 

H20,Al,S-Alunite(K2SO4.3Al203.3S03.6H20). 

H2O,  As,  Cu— Olivenite  (Cu4As269  +  H2O). 

H2O,  As,  Cu — Conichalcite  ((Cu,  Ca)4As2O9  + 
3/2H20). 

H2O,  Bi— Bismutite  (Bi2CO5-f  H2O). 

H2O,  B— Colemanite  (Ca2B«OiiH-5H2O). 

H2O,  B,  Na— Borax  (Na2B4O7  +  ioH2O). 

H2O,  Ca,  S— Gypsum  (CaSO4  +  2H2O). 
"  H2O,  Cu— Malachite  (Cu2CO4  +  H2O). 

H2O,  Cu— Azurite  (Cu3C2O7  +  H2O). 

H2O,  Cu— Crysocolla  (CuSiO3  +  2H2O). 

H2O,  Fe— Limonite  (2Fe2O3+3H2O). 

H2O,  Fe,  P— Vmanite  (Fe3P2O8+8H2O). 
1    H2O,  Mg— Talc  (Mg3Si4Oii+H2O). 

H2O,  Mn— Manganite  (Mn2O3  +  H2O). 

H2O,  Mn— Psilomelane  (MnO2  +  2H2O). 

H2O,  Ni— Garnierite  (H2(Ni,  Mg)SiO4  +  H2O). 

H2O,  Na— Natron  (Na2CO3  +  ioH2O). 

H2O,  Na— Trona  (Na2CO3.HXaCO3  -f  2H2O). 


DETERMINATION   OF   MINERALS  61 


H2O,  Zn—  Hydrozincite 

H2O,  Zn—  Calamine  (Zn2SiO4  +  H2O). 

Silicates. 

The  two  mentioned  below  are  the  only  ones  in  the 
above  list  which  will  give  the  test  for  a  silicate 
described  previously. 

Willemite  (Zn2SiO4). 

Calamine  (Zn2SiO4  +  H2O). 

Carbonates. 

Ba—  Witherite  (BaCO3). 
Bi—  Bismutite  (Bi2CO5  +  H2O)  . 
-    Ca—  Calcite  (CaCO3). 

Ca,  Mg—  Dolomite  ((Ca,  Mg)CO3). 

Cu,  H2O—  Malachite  (Cu2CO4  +  H2O). 

Cu,  H2O—  Azurite  (Cu3C2O7  +  H2O). 

Fe—  Siderite  (FeCO3). 

Pb—  Cerussite  (PbCO3). 

Mg—  Magnesite   (MgCO3). 

Mn—  Rhodochrosite  (MnCO3). 

Na,  H2O—  Natron  (Na2CO3  +  ioH2O). 

Na,  H2O—  Trona  (Na2CO3.HNaCO3+2H2O). 

Sr—  Strontianite  (SrCO3). 

Zn—  Smithsonite  (ZnCO3). 

Zn,  H2O—  Hydroeincite 


CHAPTER  VI 
THE  ELEMENTARY  PRINCIPLES  OF  CHEMISTRY 

'ERPRETAT 
SYMBOLS 

Elements.  Every  body  in  nature  is  composed 
of  one  of  more  constituent  substances  called  elements. 
Sometimes,  as  in  the  case  of  the  metals  gold,  silver, 
and  copper,  there  is  only  one  substance;  it  is  itself 
an  element.  In  other  cases  there  are  two  or  more 
elemental  constituents  present  in  the  body,  which  by 
proper  manipulation  may  be  broken  up  or  resolved 
into  its  elements. 

An  element,  is  then,  something  that  has  resisted 
all  attempts  to  subdivide  it  into  other  substances. 
It  follows,  necessarily,  that  an  element  cannot  be 
formed  by  a  union  of  other  substances. 

Each  element  differs  more  or  less  from  all  others 
in  appearance,  properties,  and  uses.  Some  are 
gases,  some  are  opaque  and  reflect  light  from  the 
surface — are  metals,  and  some  are  transparent  or 
translucent — are  non-metals.  The  distinction  be- 
tween metals  and  non-metals  is,  however,  not 
sharply  marked,  since  there  are  elements  with  inter- 

62 


ELEMENTARY  PRINCIPLES  OF  CHEMISTRY  63 

mediate  properties.  A  full  list  of  all  known  elements 
is  given  in  the  table  at  the  end  of  this  chapter. 

It  has  happened  occasionally  that  a  substance 
supposed  to  be  an  element  has  been  found  to  be 
composed  of  two  or  more  elements,  and  this  will 
probably  occur  in  the  future,  but  chemists  feel 
practically  certain  of  the  elementary  condition  of  all 
the  commoner  elements.  They  know  now  that  the 
Alchemists'  search  for  a  method  of  making  gold 
was  foredoomed  to  failure. 

Chemical  Compounds.  Elements  have  the  prop- 
erty of  uniting  under  certain  conditions  to  form 
new  substances,  differing  in  nature  from  any  of 
the  constituent  elements.  The  results  of  such  unions 
are  not  merely  mechanical  mixtures  of  the  elements 
in  which  each  component  can  be  identified  under 
the  high-power  microscope,  but  are  homogeneous 
substances  of  definite  properties,  which  will  often 
fail  to  respond  to  tests  yielded  by  their  constituent 
elements.  Such  combinations  of  two  or  more 
elements  are  called  chemical  compounds.  Thus, 
the  common  chemical  compound  water  is  composed 
of  one  gas,  hydrogen,  which  burns  in  the  air,  and 
another,  oxygen,  which  is  essential  for  respiration, 
properties  quite  foreign  to  water. 

Most  natural  bodies  are  either  chemical  compounds 
or  mixtures  of  them.  Other  peculiarities  possessed 
by  them  will  be  mentioned  later. 

Alloys.     Alloys  are  rather  indefinite  compounds 


64  BLOWPIPE   AXALYSIS 

of  metals  whose  natures  are  not  thoroughly  under- 
stood. 

Atoms.  Atoms  are  the  smallest  particles  into 
which  it  is  believed  an  element  may  be  divided  and 
still  retain  all  its  distinguishing  properties.  Although 
not  infinitely  small,  they  are  far  too  minute  to  be 
seen  with  the  microscope,  yet  there  are  abundant 
more  or  less  indirect  proofs  of  the  correctness  of 
the  atomic  theory.  That  atoms  are  themselves 
subdivisible  is  now  admitted,  but  these  lesser  par- 
ticles reveal  the  characteristic  properties  of  entirely 
different  elements  from  those  which  they  formed 
before  disintegration,  and  are  produced  only  under 
very  unusual  conditions,  probably  never,  or  very 
rarely,  duplicated  in  chemical  operations. 

According  to  the  atomic  theory,  the  atoms  of  any 
element  have  the  same  weight  and  size  and  are 
identically  alike,  while  the  atoms  of  different  ele- 
ments have  different  weights  and  sizes,  and  further 
differ  to  the  same  extent  as  do  the  elements 
themselves. 

Molecules.  Molecules  are  the  smallest  particles 
into  which  it  is  believed  a  chemical  compound  may 
be  divided  and  still  remain  the  same  chemical 
compound.  They  must  consist,  evidently,  of  at  least 
two,  and  often  several,  atoms.  The  same  word 
(molecule)  is  also  applied  to  the  smallest  volumes 
of  a  gas,  even  though  it  be  an  element  instead  of  a 
compound,  since  it  appears  certain  that  the  smallest 


ELEMENTARY  PRINCIPLES  OF  CHEMISTRY   65 

particles  of  gases  always  consist  of  at  least  two 
atoms. 

With  certain  modifications  that  it  is  not  necessary 
to  discuss,  it  may  be  stated  that  the  number  of 
atoms  present  in  a  molecule  of  a  given  chemical 
compound  is  always  the  same,  and  that  the  different 
atoms  forming  a  molecule  of  a  certain  chemical 
compound  are  always  present  in  a  fixed  proportion. 
Thus,  a  molecule  of  water  always  contains  two 
atoms  of  hydrogen  and  one  atom  of  oxygen. 

Symbols.  For  convenience,  the  elements  are 
represented  by  the  initial  letter,  either  alone  or  with 
an  added  letter,  of  their  Latin  or  Greek  names, 
which  are  in  many  cases  very  similar  to  their  English 
names.  These  letters  are  called  the  symbols  of 
the  elements. 

Formulae.  The  formula  of  a  chemical  compound 
is  written  by  placing  the  symbols  of  its  component 
elements  in  a  line,  and,  if  more  than  one  atom  of 
any  of  these  is  present  in  the  molecule  of  the  com- 
pound, the  number  of  such  atoms  is  indicated  by 
subscripts  written  after  the  symbols  of  the  elements 
thus  affected.  Thus,  the  formula  of  water  is  H^O, 
indicating  that  the  molecule  of  water  contains  two 
atoms  of  H  combined  with  one  atom  of  O.  This 
formula  is  read  h-two-o. 

It  is  sometimes  possible  to  group  the  atoms  in 
the  formula  of  a  complex  substance  in  such  a  fashion 
as  to  form  two  or  more  groups  of  molecules,  indicat- 


66  BLOWPIPE  ANALYSIS 

ing  that  the  substance  may  be  formed  not  only  by 
a  union  of  atoms  but  also  by  a  combination  of 
molecules.  Such  formulae  may  be  written  with  a 
period  separating  the  constituent  molecules.  Thus, 
CaCOs  (read  c-a-c-o-three)  is  the  symbol  of  calcite, 
of  which  marble  is  a  variety,  and  this  formula  may 
be  written  CaO.CO2)  indicating  that  the  material 
is  formed  by  the  union  of  one  molecule  of  lime 
(CaO)  and  one  of  carbonic  acid  gas  (CO2).  When 
it  is  possible  to  break  up  a  formula  into  molecules 
in  this  way,  it  is  often  found  that  more  than  one 
of  a  certain  constituent  molecule  is  present  in 
substance.  Thus,  the  ordinary  formula  of  ortho- 
clase  feldspar  is  KAlSi3O8,  but,  after  multiplying 
each  atom  by  two,  this  is  found  to  consist  of  one 
molecule  of  potassium  oxide  (K2O),  one  of  alumina 
(A12O3),  and  six  of  silica  (SiO2),  and  may  therefore 
be  written  K2O.Al2O3.6SiO2.  The  order  in  which 
the  different  molecules  are  written  is  of  no  great 
importance;  the  above  formula  might  with  equal 
correctness  be  written  6SiO2.K2O.Al2O3,  although 
this  is  not  the  customary  order.  It  should  be 
noticed  that  a  figure  prefixed  to  a  molecule,  as  in 
the  case  of  the  6  in  the  above  formula,  applies  only 
to  the  molecule  to  which  it  is  prefixed. 

Sometimes  formulas  like  the  following  (the  formula 
of  emerald)  are  used:  Be3Al2(SiO3)6.  This  is  read 
b-e-three-a-1-two  -  parenthesis-s  -  i-o  -  three  -  taken  -  six- 
times.  Both  the  Si  and  the  O  in  the  parenthesis  are 


ELEMENTARY  PRINCIPLES  OF  CHEMISTRY  67 

affected  by  the  subscript  6  and  might  be  written 
Si6Oi8,  but  it  is  sometimes  desirable  to  group  ele- 
ments in  parentheses  in  this  way.  Groups  like  this 
are  not  molecules  since  they  do  not  occur  as  known 
chemical  compounds. 

A  different  use  of  the  parenthesis  is  seen  in  the 
case  of  those  compounds  in  which  the  relative  pro- 
portions of  certain  compounds  are  apt  to  vary — 
apparently  a  modification  or  violation  of  a  previously 
expressed  law.  Thus,  a  common  constituent  of 
limestone  is  a  mineral  called  dolomite,  whose  formula 
is  (Mg,Ca)CO3.  Here  the  comma  between  the 
Mg  and  Ca  indicates  that  the  relative  proportion 
of  Mg  and  Ca  is  not  fixed;  there  may  be  a  nearly 
or  quite  equal  number  of  atoms  of  both  present, 
or  either  may  predominate  to  a  small  or  great 
extent  over  the  other.  In  an  instance  like  this  the 
element  first  written  in  the  parenthesis  is  apt  to  be 
the  more  plentiful.  Sometimes  it  is  more  con- 
venient (as  when  the  horizontal  space  is  limited) 
to  write  the  variable  elements  in  such  formulae  in  a 
vertical  column  without  using  the  comma,  in  this 

manner:   ( 

\ 

Atomic  weights.  The  atomic  weight  of  an 
element  is  the  relative  weight  of  an  atom  of  the 
element  compared  with  the  weight  of  an  atom  of 
H,  which  is  taken  as  unity,  it  being  the  lightest 
known  element.  Thus,  an  atom  of  Fe  is  fifty-six 


68  BLOIVPII'E   AXAI.YSIS 

times  as  heavy  as  an  atom  of  H,  so  the  atomic  weight 
of  Fe  is  56.  A  presentation  of  the  methods  by 
which  the  atomic  weights  of  the  various  elements 
are  determined  is  not  necessary,  but  these  atomic 
weights  have  a  practical  use  which  is  important. 
This  may  be  illustrated  as  follows:  Since  pure 
water  is  composed  entirely  of  molecules  having 
the  formula  H2O,  if  wt  know  the  relative  weights 
of  the  H  and  O  atoms,  it  should  be  a  simple 
matter  to  calculate  the  proportions  by  weight  of 
H  and  O  in  the  molecule,  and  thus  to  determine 
the  proportion  by  weight  of  these  elements  in  any 
amount  of  the  substance.  There  being  two  atoms 
of  H  present  in  the  molecule,  each  of  which 
weighs  one  unit  (atomic  weight  of  H  is  i), 
and  one  atom  of  O,  which  weighs  sixteen  units 
(atomic  weight  of  O  is  16),  the  whole  molecule 
must  weigh  2  +  16=18.  units.  It  is  plain  that 
the  H  must  constitute  2/i8,  or  1/g,  and  the  O 
form  16/i8>  or  8/9  of  the  whole  molecule.  It  fol- 
lows that  pure  water  in  any  amount  is  1/9  H  and 

8/9o. 

In  this  way  it  is  always  possible  to  calculate  the 
relative  proportions  of  the  different  elements  in  a 
substance  whose  formula  is  known,  provided  no 
elements  involved  occur  in  variable  quantities, 
indicated  by  placing  them,  separated  by  commas, 
in  parentheses,  or  in  vertical  columns  in  parentheses, 
as  previously  explained.  The  atomic  weights  of 


ELEMENTARY  PRINCIPLES  OF  CHEMISTRY   69 

all  the  elements  are  given  in  the  table  at  the  end 
of  this  chapter. 

Suppose,  for  illustration,  it  be  required  to  find 
how  many  pounds  of  each  of  the  component  elements 
there  are  in  100  pounds  of  pure  marble,  with  the 
formula  CaCO3.  Let  the  abbreviation  A.W.  mean 
atomic  weight,  then — 

A.W.  Ca=40.     Total  weight  of  the  one    Ca  atom 

=  40  H  units. 
A.W.   C=i2.     Total  weight  of  the  one    C    atom 

=  12  H  units. 
A.W.  O  =  i6.     Total  weight  of  the  three  O  atoms 

=48  (3X16)  H  units. 

Total  weight  of  the  molecule  =  100  H  units. 
Ca  present  is  4%oo  of  whole  =  40%  =  40  pounds. 
C  present  is  12/ioo  of  whole  =12%  =12  pounds. 
O  present  is  48/ioo  of  whole  =  48%  =  48  pounds. 

As  a  still  more  complex  case,  let  it  be  required 
to  ascertain  the  amount  of  Zn  and  H2O  in  100  pounds 
of  hydrozincite,  with  the  formula  3ZnCO3  +  2H2O. 

A.W.  Zn  =  65-4.      Number    of    atoms     of    Zn  =  3> 

Weight  of  three  Zn  atoms  (3X65.4)  =  196.2. 
A.W.  C=i2.  "Number  of  atoms  of  €  =  3.     Weight 

of  three  C  atoms  (3X12)=  36. 
A.W.  O  =  1 6.     Number  of  atoms  of  O  =  1 1.    Weight 

of  eleven  O  atoms  (nXi6)  =  i76. 
A.W.  H=i.     Number  of  atoms  of  H  =  4.     Weight 

of  four  H  atoms  (4X1)  =4. 


70  BLOWPIPE  AXALYSIS 

Weight  of  molecule  (in  H  units)  -=412.2. 

Zn    present  is    196-2/412.2    of    whole  =  47. 6%  =  47. 6 

pounds. 
H2O  present  is  36  4V2.2  of  whole  =  8. 7%  =  8. 7  pounds. 

Molecular  Weights.  The  molecular  weight  of  a 
molecule  or  chemical  compound  is  the  sum  of  the 
atomic  weights  of  the  elements  forming  the  molecule 
or  compound,  taking  the  atomic  weight  of  each 
element  as  many  times  as  there  are  atoms  of  that 
element  present. 

Acids.  Acids  are  substances  that  impart  a  red 
coloration  to  blue  litmus  paper.  Two  kinds  are 
recognized:  the  halogen  acids,  compounds  of  H 
and  one  of  the  so-called  halogen  elements,  Cl,  F,  Br, 
and  I,  and  the  oxygen  acids,  compounds  of  O  and 
H  with  some  other  element. 

Sometimes  several  acids  are  formed  by  using 
different  proportions  of  the  same  elements.  The 
termination  "  ous  "  is  then  used  in  the  name  of 
the  one  with  a  relatively  low  percentage  of  O,  and 
the  termination  "  ic  "  in  the  name  of  the  one  with 
a  relatively  high  percentage  of  that  element.  Thus, 
H2SO3  is  sulphurous,  and  H2SO4  is  sulphuric 
acid. 

Among  the  other  commoner  inorganic  acids  are 
the  following:  Hydrochloric  (HC1),  hydrofluoric 
(HF),  silicic  (H4SiO4),  carbonic  (H2CO3),  nitric 
(HNOa),  boric  or  boracic  (H^BOs),  and  phosphoric 
(H3P04). 


ELEMENTARY  PRINCIPLES  OF  CHEMISTRY  71 

Bases,  Salts,  and  Chemical  Equations.  Bases 
are  such  substances  as  impart  a  blue  color  to  red 
litmus  paper,  or  which  are  capable  of  replacing  all 
or  part  of  the  H  in  an  acid  and  forming  a  substance 
called  a  salt.  Bases  are  always  metals,  combina- 
tions of  metal  and  O,  or  the  latter  with  the  addition 
of  H.  Thus,  when  Na  (a  base)  is  added  to  HC1 
(an  acid),  NaCl  (a  salt)  is  formed  and  H  is  liberated. 
Such  changes  as  this,  called  chemical  reactions, 
may  be  expressed  in  the  form  of  an  equation,  thus: 
HCl  +  Na  =  NaCl  +  H. 

ZnO  (base)+2HNO3  (acid)=Zn(NO3)2  (salt)  + 
H2O  (water). 

The  opposite  sides  of  chemical  equations  must 
always  contain  the  same  number  of  atoms  of  each 
element  involved.  When  this  is  true,  they  are  said 
to  balance. 

From  the  above  discussion,  it  is  plain  that  a  salt 
may  be  defined  as  a  compound  that  is  formed  by  the 
reaction  of  an  acid  and  a  base;  all  or  part  of  the 
H  in  the  acid  is  replaced  by  one  or  more  metals. 

If  a  salt  is  formed  from  an  acid  with  the  "  ous  " 
termination,  its  name  terminates  in  "  ite."  Thus, 
NagSOs  (formed  from  sulphurous  acid)  is  known 
as  sodium  sulphite  or  sulphite  of  sodium.  When 
the  salt  is  formed  from  an  acid  with  the  "  ic  " 
termination,  its  name  terminates  in  "  ate."  Thus, 
the  Zn(NO3)2  obtained  in  the  reaction  recently 
equated  is  called  zinc  nitrate  or  nitrate  of  zinc. 


72  BLOWPIPE  AXALYSIS 

In  cases  where  lack  of  knowledge  makes  it 
impossible  to  decide  whether  an  "  ic  "  or  an  "  ous  " 
acid  was  involved  in  the  formation  of  a  salt,  it  is 
usually  safe  to  use  the  "  ate  " — the  commoner- 
termination,  calling  the  salts  sulphates,  carbonates, 
phosphates,  etc. 

Additional  Nomenclature.  When  an  element 
is  combined  with  a  non-metal,  the  resulting  com- 
pound is  named  by  adding  the  termination  "  ide  " 
to  the  root  of  the  name  of  the  non-metal.  The 
following  list  will  illustrate  this  usage:  FeAs2  is 
iron  arsenide  or  arsenide  of  iron,  A^CUfis  chloride 
of  silver,  AuTe2  is  telluride  of  lead,  and  Fe2O3  is 
oxide  of  iron. 

Sometimes  compounds  of  this  type  are  formed 
in  which  more  than  one  element  combines  with  the 
non-metal,  or  one  element  may  combine  with 
two  different  non-metals,  as  in  the  following 
instances:  CuFeS2  is  copper,  iron  sulphide,  and 
Co2As2S2  (CoS2.CoAs2)  is  cobalt  arsenide  and 
sulphide.  Care  should  be  taken  not  to  confuse  the 
"  ite  "  and  "  ide  "  terminations. 


ELEMENTARY  PRINCIPLES  OF  CHEMISTRY   73 


TABLE    OF    ELEMENTS    WITH    THEIR    SYMBOLS    AND 
ATOMIC   WEIGHTS 


Name. 

Sym- 
bol. 

At. 
Wts. 

Name. 

Sym- 
bol. 

At. 
Wts. 

Al  minum 

Al 

Nd 

6 

. 

Sb 

Neon 

Ne 

n  imony  

A 

Nickel 

Ni 

58    7 

A  8  ' 

As 

N 

R 

Ba 

Os 

Beryllium  
Bismuth  

Be 
Bi 
B 

9-1 
208.  5 

Oxygen  
Palladium  

o 

Pd 
p 

16 
106.5 

B  ' 

Br 

79  96 

Platinum  

Pt 

Cadmium  

Cd 
Cs 

112.4 

Potassium  

K 
Pr 

39-iS 

Calcium  

Ca 

c 

40.1 

Radium  
Rhodium 

Ra 

Rh 

225 

Cerium  
Chlorine  
Chromium  
Cobaft  
Columbium  
Copper  

Ce 
Cl 
Cr 
Co 
Cb 
Cu 
Er 

140.25 
35-45 
52-' 
59 
94 
6.?  .  6 
1  66 

Rubidium  
Ruthenium  
Samarium  
Scandium  
Selenium  
Silicon  
Silver  

Rb 
Ru 
Sm 
Sc 
Se 
Si 
Ag 

85.4 
101.7 
15° 
44.1 
79-2 
28.4 

F 

Sodium 

Na 

Gadolinium  
Gallium  
Germanium  
Gold  

Gd 
Ga 
Ge 
Au 
He 

IS'' 
70 
72-5 
197-2 

Strontium  
Sulphur  
Tantalum  
Tellurium  

Sr 
S 
Ta 
Te 
Tb 

87-6 
32  .06 
183 
127.6 
1  60 

H  -d 

H 

Thallium 

Tl 

Ind;um  

In 
I 

114 
126   85 

Thorium  
Thulium 

Th 
Tm 

232.5 

Iridium  

Ir 
Fe 

193 

Tin  

Sn 
Ti 

119 
48    I 

Krypton  
Lanthanum  
Lead  
Lithium  
Magnesium  
Manganese  
Mercury  
Molybdenum  

Kr 
La 
Pb 
Li 
Mg 
Mn 
Hg 
Mo 

81. 
138. 
206. 
7-    3 
24.36 
55 
200 

96 

Tungsten  
Uranium  
Vanadium  
Xenon  
Ytterbium  
Yttrium  '.  .  . 
1  Zinc  
:  Zirconium  
i 

W 
IT 
V 
Xe 
Yb 
Yt 
Zn 
Zr 

184 
238.S 
51-2 
128 
'73 
89 
65-4 
90.6 

INDEX 


PAGE 

Acids  (defined) 70 

Alloys  (defined) 63 

Aluminum,  minerals  containing 51 

Aluminum,  test  for 48 

Antimony,  minerals  containing 52 

Antimony,  tests  for 48 

Anvil 4 

Arsenic,  minerals  containing 52 

Arsenic,  tests  for 48 

Assay  (defined) 10 

"  ate  "  termination  of  salts 71 

Atomic  weight  (defined) 67 

Atomic  weights,  table  of 73 

Atoms  (defined) 64 

Barium,  minerals  containing 53 

Barium,  tests  for 48 

Bases  (defined) 71 

Bead  tests,  borax 25 

Bead  tests,  microcosmic  salt 32 

Bead  tests,  salt  of  phosphorus -  -  32 

Bead  tests,  sodium  ammonium  phosphate 32 

Bead  tests,  table  of 30 

Bismuth  flux  (defined) 5 

Bismuth,  minerals  containing 53 

Bismuth,  tests  for 48 

Blast,  production  of ...  6 

Blowpipe ....  i 

Blowpipe  analysis  (defined) 9 


76  INDEX 


Blowpipe  analysis,  outline  for  ...........................  4^ 

Blowpipe  operations  ....................................  r> 

Borax  beads,  tests  with  .................................  25 

Boron,  minerals  containing  ..............................  j  ^ 

Boron,  tests  for.  .  ......................................  48 

Cadmium,  minerals  containing  ...........................  c^ 

Cadmium,  tests  for  ...............................  ......  48 

Calcium,  minerals  containing  ............................  ^ 

Calcium,  tests  for  ......................................  48 

Carbonate  minerals  .....................................  6  1 

Carbonate,  test  for  a  ....................................  49 

Charcoal  borer  .........................................  c; 

Charcoal  supports  ......................................  3 

Chemical  compound  (defined)  .....................  *.  .....  63 

Chemical  equations  .....................................  71 

Chemistry,  elementary  principles  of  .......................  62 

Chromium,  minerals  containing  ..........................  5  ; 

Chromium,  tests  for  ....................................  48 

Closed  tubes  ...........................................  4 

Closed  tubes,  tests  in  ..............  .  .....................  19 

Cobalt  nitrate  coloration  tests  ............................  39 

Cobalt,  minerals  containing  .............................  ^4 

Cobalt,  tests  for  .......................................  48 

Compounds,  chemical  (defined)  ..........................  63 

Copper,  minerals  containing  .............................  ^4 

Copper,  tests  for  .......................  ................  48 

Decrepitation  (defined).  ...                ............                     .  .  1  1 

Determination  of  minerals  ...............................  50 

Elements  (defined)  .....................................  62 

Elements  detectable  with  the  blowpipe  ....................  9 

Elements,  table  of  all  ...................................  73 

Flame,  hottest  .........................................  8 

Flame,  oxidizing  .......................................  9 


IXDEX  77 

PAOB 

Flame,  reducing 8 

Flame  tests ^ 

Fluorine,  minerals  containing ^4 

Fluorine,  tests  for 48 

Flux 1 6 

Forceps,  platinum-tipped ^ 

1'ormuhc  (defined) 65 

Gold,  minerals  containing 54 

Gold,  tesls  for 48 

Hammer 4 

Holder  for  platinum   wire -5 

Holders  for  tubes 4 

"  ic  "  termination  of  acids 71 

"  ide  "  termination  of  salts , . . .  72 

Index  to  minerals  containing  the  various  elements 51 

Index  to  tests  yielded  by  the  various  elements 47 

Instruments  user!  in  blowpipe  analysis i 

Iron,  minerals  containing , 55 

Iron,  tests  for 48 

"  ite  "  termination  of  salts 71 

Lamps 2 

Lead,  minerals  containing 55 

Lead,  tests  for 48 

Lithium,  7ninerals  containing 55 

Lithium,  tests  for. 48 

Magnesium,  minerals  containing 56 

Magnesium,  tests  for 48 

Ma-net 4 

Manganese,  minerals  containing 56 

Manganese,  tests  for 48 

Mercury,  minerals  containing 56 

Mercury,  tests  for 4<S 


78  IXDEX 


Microcosmic  salt  l>eads,  tests  with 

Minerals  containing  the  various  elements. 

Minerals,  determination  of 

Molecular  weight  (defined) 

Molecules  (defined) 

Molybdenum,  minerals  containing 

Molybdenum,  tests  for 


Nickel,  minerals  containing. 
Nickel,  tests  for 


Oil  for  lamp .  j 

Open  tubes ! 

Open  tubes,  tests  in _>  ^ 

"  ous  "  termination  of  acids 71 

Outline  for  qualitative  blowpipe  analysis ^ 

Oxidizing  flame 7 

Parenthesis,  use  of  (in  chemical  formuh:) 66 

Phosphorus,  minerals  containing ^6 

Phosphorus,  tests  for 48 

Platinum-tipped  forceps 3 

Platinum  wire 3 

Platinum  wire  holders 3 

Potassium,  minerals  containing 57 

Potassium,  tests  for 48 

Qualitative  analysis  (defined).  .  '. 42 

Quantitative  analysis  (defined) 42 

Reagent  bottles 5 

Reagents 5 

Reducing  flame 8 

Salt  of  phosphorus  l^eads,  tests  with 32 

Salts  (defined) 71 

Saturated  bead  (defined) 27 


79 


PAGE 

Selenium,  minerals  containing 57 

Selenium,  tests  for 48 

Silicate  minerals 61 

Silicate,  test  for  a 49 

Silver,  minerals  containing ^7 

Silver,  tests  for  .  . ., 48 

Sodium  ammonium  phosphate  lx;ads,  tests  with 32 

Sodium,  minerals  containing ^7 

Sodium,  tests  for 48 

Strontium,  minerals  containing 57 

Strontium,  tests  for 49 

Sublimates  (defined) 10 

Sulphur,  minerals  containing 58 

Sulphur,  tests  for 49 

Symbols  (defined) 65 

Table  of  bead  tests 30 

Tellurium,  minerals  containing 59 

Tellurium,  tests  for 49 

Tests,  flame 33 

Tests  for  the  various  elements,  index  to 47 

Tests  in  closed  tubes  with  acid  potassium  sulphate 22 

Tests  in  closed  tubes  without  flux 20 

Tests  in  closed  tubes  with  sodium  carbonate  flux 22 

Tests  in  open  tubes 23 

Tests  with  acids 40 

Tests  with  borax  beads 25 

Tests  with  cobalt  nitrate  (coloration  tests). '. 39 

Tests  with  microcosmic  salt  beads 33 

Tests  with  salt  of  phosphorus  beads 32 

Tests  with  sodium  ammonium  phosphate  lx:ads.  .  .  ." 33 

Tin,  minerals  containing 59 

Tin,  tests  for 49 

Titanium,  minerals  containing 59 

Titanium,  tests  for 49 

Treatment  on  charcoal  with  flux 15 

Treatment  on  charcoal  without  flux  .  .  . .  10 


80  IXDEX 


PAGE 

Tubes,  closed 4 

Tubes,  open 4 

Tungsten,  minerals  containing 59 

Tungsten,  tests  for 40 

Uranium,  minerals  containing 50 

Uranium,  tests  for  ....            49 

Vanadium,  minerals  (  ontaining ^g 

Vanadium,  tests  for 49 

Volatile  (defined) 12 

Water,  minerals  containing 60 

Water,  tests  for.  . 49 

Wire,  platinum } 

Zinc,  minerals  containing 50 

Zinc,  tests  for 19 


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